Passive Transport
Objectives:
Any type of cellular transport that doesn’t require any energy input is called passive transport. Since large molecules, charged ions, and polar molecules cannot readily cross the membrane transport proteins provide a way for them to enter and exit the cell. This is called facilitated diffusion because it is helped by proteins. Facilitated diffusion is also a form of passive transport so it requires no energy. Facilitated diffusion uses transport proteins to move a substance down its concentration gradient. A transport protein is a protein built into the plasma membrane that helps certain kinds of molecules or ions pass through. When a dissolved substance is more concentrated in one area it forms a concentration gradient. A concentration gradient is a gradual difference in the concentration of a substance in a solution as a function of distance. The movement of a dissolved substance down a concentration gradient is called diffusion. It stops when equilibrium is reached and requires no energy. Osmosis is the movement of water from areas of higher water concentration to areas of lower water concentration. It is also passive transport and requires no energy. A hypotonic fluid has a lower concentration of dissolved substances than a cell’s interior. An isotonic fluid has an equal concentration of dissolved substances to a cell’s interior. A hypertonic fluid has a greater concentration of dissolved substances than a cell’s interior. Questions
2. When a substance is more concentrated in one area it forms what?
3. A fluid that has a greater concentration of dissolved substances than a cell’s interior is called what?
4. Explain how facilitated diffusion differs from diffusion. Answer: Facilitated diffusion requires transport proteins to function properly and diffusion requires a concentration gradient. 5. Explain the process that occured in the picture above. Answer: Osmosis moved the water from the right side of the beaker to the left side in order to reach equilibrium. Active Transport Objectives
Active transport is the movement of particles from an area of low concentration across a membrane to an area of high concentration. This type of transport requires energy in the form of ATP. A common type of active transport is the use of membrane proteins called ion pumps and molecular pumps. They use ATP to move substances against a concentration gradient. Ion pumps move ions. Molecular pumps move uncharged molecules. Macromolecules are usually too big to pass through the cell membrane so the cell uses vesicles to move them in and out of the cell. Vesicles are small membrane sacs that transport material throughout the cytoplasm. In exocytosis a vesicle moves toward the membrane and fuses with it. Then it releases substances outside of the cell. In endocytosis a vesicle that is already fused with the membrane takes in substances from outside the cell and releases it in the cytoplasm. Questions
2. How does a cell take in materials from extracellular fluid and release it into the cell?
3. What is the purpose of ion pumps?
4. Explain the process of exocytosis. Answer: Exocytosis is the process where vesicles take substances from the cytoplasm and fuses with the cell membrane to release the substances outside the cell. 5. What are vesicles? Answer: Vesicles are small membrane sacs that transport material throughout the cytoplasm. Homeostasis Objectives
Homeostasis is the process the body goes through to maintain a constant internal state of balance. The processes by which an organism monitors and maintains a constant state, such as temperature, is a homeostatic mechanism. To maintain homeostasis, the body may rely on a cycle of monitoring and responding to internal conditions, called a negative feedback loop. A negative feedback loop reacts to any change to a system and causes the system to return to its original state. A positive feedback loop does the exact opposite of a negative feedback loop. The positive loops amplify a change to a system and moves it farther from its original state. An example of positive feedback is if the a blood vessel gets cut the body sends platelets to plug the cut and the platelets release hormones to signal other platelets to come as well until the cut is completely sealed. Thermoregulation controls the body’s temperature and relies on negative feedback to bring the body’s temperature back to its original state. Examples of this are if the body gets cold it shivers to produce heat. Osmoregulation is the process the body goes through to regulate the balance of water and solutes. This type of regulation also relies on negative feedback. An example of this is if the body has too much water in the body it sends signals to urinate in order to release the excess fluid. The body’s cells require oxygen to carry out respiration, which produces carbon dioxide. The levels of dissolved oxygen and carbon dioxide are regulated by gas exchange. The gas exchange makes sure that the body has healthy balance of oxygen and carbon dioxide. The human body requires a blood glucose level of around 90 mg. Blood glucose regulation relies on negative feedback to control the glucose levels. Questions
2. Sweating due to overheating is an example of…
3. Osmoregulation controls which of the following?
4. Describe how a person’s body would react to a blood vessel getting cut. Answer: The body would send platelets to seal the cut and the platelets would signal for more to come help seal the cut creating a positive feedback loop.
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BIOENERGETICS: ATP, CELLULAR RESPIRATION, and PHOTOSYNTHESIS
BIO.A.3.1.1, A.3.2.1,A.3.2.2 ATP and Cellular Respiration How does a cell provide energy to power its metabolic reactions? Reactions release energy, but many consume energy. How does the cell provide energy to power its reactions. The body uses ATP as energy and it provides energy for the processes in Cellular respiration. It is known as the “energy currency” in cells. It has 3 Phosphate groups, when the end phosphate group is disconnected, it releases energy and become ADP. This creates a repeating cycle of ATP being broken down and re-formed in cells. ATP is being used over and over in the process of CELLULAR RESPIRATION. In the first stage of Cellular Respiration, glucose molecules are being broken down into smaller molecules during glycolysis (the splitting of sugars). This process occurs without the use of Oxygen and only 2 molecules of ATP form from the energy released from a glucose molecule. This is an Anaerobic respiration & it releases less energy (ATP) stored in glucose than aerobic respiration does. In the second and third stages, aerobic respirations take place in the mitochondria, which are organelles in animal & plant cells that produce energy/ATP for the cell. The process happens in the Matrix of the mitochondria. In the matrix enzymes help break down the products of glucose further in a series of chemical reaction, from this carbon dioxides are produced. During the first 2 stages, Hydrogen ions are building up in the matrix and at the third stage, these ions flow across the inner membrane of the organel. As this is happening, an enzyme called ATP synthase is powered, and this enzyme is attached to the inner membrane. It synthesis ATP from ADP and phosphate. ATP is produced as the ions exit the matrix. Tips:
Questions
Answer key
BIO .A.3.1.1, A.3.2.1, A.3.2.2 Photosynthesis Where do we receive oxygen and food from? Photosynthesis is a process that converts light energy from the sun into chemical energy stored in sugars like glucose. Photosynthetic organisms use sunlight to produce glucose and oxygen from carbon dioxide and water. The glucose made from photosynthesis can be used right away or saved for later. Plants can carry cellular respiration like animals do. The equation for cellular respiration is opposite of photosynthesis. Chloroplasts are the organelles where photosynthesis takes place in cells. A chloroplast have have 2 membranes that surround stomata/ inner fluid, and in the stromata there are disks called thylakoids. These disks contain chlorophyll, this pigment captures energy from sunlight & this is the energy that drives photosynthesis. The leaf cells take carbon dioxide through openings called stomata and plants open up their stomata to take in carbon dioxide and release oxygen. There are 2 stages of Photosynthesis and it occurs in the different parts of the chloroplast. The first stage is a light dependent, this is happening inside the thylakoid, where the chlorophyll takes in sunlight and, water molecules are being split to prepare for the next stage. ATP and other energy-rich molecules are produced and oxygen is being released from the leaf. This is the light-dependent reaction. The second stage is the light-independent reaction (also called Calvin cycle) require no light. It takes place in the stroma of the chloroplast and this reaction depends on the energy produced by the light-dependent reactions. Organic compounds (contain carbon and hydrogen, they are used to build glucose and other important molecules) and Carbon dioxide are being converted into organic molecules such as glucose. Tips: - Plants can do both photosynthesis and cellular respiration.
Questions
Chemical Basis of Life:
A.211: Introduction: Most of an organism’s cells are made up of water. Human bodies have on average, over 65% containing water. Water molecules consist of two hydrogen and one oxygen atom. They are bonded together through covalent bond. Covalent bond is bonded through atoms that share the electrons. However, this may not be the case as covalent bonds do not always share the same electrons equally. Different parts of water carry different charges, making it a polar molecule. Since water molecules are polar, they form hydrogen bond interactions with each other. Water can be considered the Universal Solvent as it can dissolve many other polar and ionic substances. However, some substances cannot dissolve in water, such as Lipids. Lipids are composed of nonpolar molecules which means that it is insoluble in water. The hydrogen bonding interactions between the water molecules give water the property of cohesion. Cohesion is the tendency of water molecules to attract and stick together. Whereas adhesion is the tendency for water to stick to other surfaces. Meniscus is the curve of water near the surface because of adhesive forces. (Refer to the picture below) With cohesion and adhesion, plants are able to move water through their own roots due to their ability that allows liquid to flow against gravity. This is known as the capillary action, or capillarity. Water also has a high capacity to absorb and hold heat, known as specific heat. Specific heat is the amount of heat energy needed to increase temperature of the substance. When a liquid absorbs enough heat, evaporation occurs changing the liquid into a gas. When water reaches its freezing point the water molecules begin to arrange itself into an orderly structure leaving more space in between. Due to ice being less dense than liquid water, it begins to float. Tips for Testing:
Practice Test: A plant is transporting water through its roots, it goes up the root despite going against its gravity. What is this known as?
Answer: A is correct because Capillary Action is when liquids move against its gravity. A team of scientists discovered that water droplets are sticking to the surface of the house after a slight rainfall. What is this known as?
Answer: B is correct because Adhesion is when water has the tendency to stick to a surface. (Continue off of the previous question) After analysing the water droplets further, they realized that the water droplets are slightly being pushed together. Combining together to form a bigger droplet. This is known as?
Answer: D is correct because Cohesion is when water has the tendency to attract other water molecules and stick together. Another scientist, Holly, analyzes the river and notices that there are ice sheets floating downward. She also notes down in her notebook that the sheets of ice were slowly floating downstream. What is the main cause of this and what characteristics does the ice have? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Answer: The main cause of this would be the freezing point of water being just around 0 degrees Celsius. If the ice is moving slowly downstream, it can be concluded that the ice is highly dense. Holly decides to take a sample of the river water with a jar. She then pours the contents over to a test tube but notices that the murky water was forming a weird curve at the very top of the tube. She measures 5mL of murky water with the graduated cylinder. What is this known as and what is the cause of it? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Answer: This is known as meniscus, meniscus is when the adhesive force between the water molecules and the container. Forming the oddly shaped curve at the very top of the tube. A 221, A222, A223: Introduction: When atoms share the same electrons, covalent bonds are formed. Hydrogen atoms can form single covalent bonds with another atom and Oxygen can form up to two bonds. So what is special about Carbon? Carbon can hold up to four covalent bonds! Carbon atoms are stable when all of the four “slots” are filled. Carbon can hold four hydrogen atoms, the organic molecule is known as methane. Organic molecules contain carbon atoms that are bonded to hydrogen atoms. Covalent bonds can be single, double, or triple bonds. For a single bond, a pair of electron is shared between the two atoms. For a double bond, two pairs are shared and three are shared in a triple bond. The unique structure of carbon allows formation of Macromolecules. Macromolecules are large complex molecules with chains of smaller molecules. Lipids would be an example of a Macromolecule. Lipids include fats, oils, waxes, and sterols. Fatty acid “tails” are connected to the glycerol molecule and produces a long chain of carbon atoms connected to each other. Lipids consist almost entirely of hydrogen and carbon atoms with few oxygen atoms. (Refer to the picture below for overview of Lipids) Fatty acids can be saturated or unsaturated. Saturated fatty acids have carbons which have maximum number of single bonds. Unsaturated fatty acid has fewer than maximum number of bonds. Lipids have important functions. Energy Storage Organism convert organic molecules to lipids to store energy. Cell Membranes Phospholipids help to form the plasma membrane for the cell. Phospholipids contain a polar phosphate attached to glycerol. Insulation and protection Fats help insulate the body and protect the major organs. Chemical messengers Class of lipids, the sterols, act as chemical messengers or hormones. The plasma membrane is formed up of phospholipids. Phospholipids are major components of cell membranes. Lipid portions are nonpolar, therefore, impermeable to water. Two fatty acid chains make up the nonpolar tails, while the phosphate group is the polar head. The fatty acid tails are nonpolar whereas the head is polar. Carbohydrates consist of carbon, hydrogen, and oxygen. Glucose is a compound used by cells for energy. Glucose is the simplest type of carbohydrate, a monosaccharide. Monosaccharides can be linked up together in chains to form bigger macromolecules. Monomers are smaller building block molecules that combine to form large polymers. Glucose can link together to form various polysaccharides such as starch, glycogen, and cellulose. Starch is a complex carbohydrate produced by plants to store their energy. Glycogen is the human equivalent of starch, which can be found in the livers and muscle. Cellulose is a structural carbohydrate that makes the plant cell walls. Carbohydrates also have many different functions. Cellular respiration Carbohydrates are digested to glucose, and used in cell respiration. Energy storage Glycogen and starch can store energy for animals and plants. Structure Cellulose gives strength to the Cell wall. Organisms have specific chemical reactions that join monomers together and breaks the polymers apart. Dehydration synthesis occurs when two monomers join together. Dehydration synthesis joins monomers together to form larger polymers and water is produced as a by product. During Dehydration synthesis, the two -OH groups join together losing the hydrogen atoms and one oxygen atom. Hydrolysis is when organism need to break down polymers into monomers. In this reaction, the -OH groups are added back from the water molecule. Tips for Testing:
Practice Test: The Monomer of a Polysaccharide is:
Answer: B is correct because the monosaccharide is the monomer of a disaccharide. How many covalent bonds can carbon form with Hydrogen atoms? Also, what is special about Carbon and Macromolecules?
Answer: C is the correct choice because carbon is special to Macromolecules because the special structure allows the formation of it. Carbon can form 4 covalent bonds with hydrogen atoms. What do Monosaccharides and Polysaccharides consist of?
Answer: A is correct because monosaccharides consist of Glucose, Fructose, and Galactose. Polysaccharides consist of Glycogen, Starch and Cellulose. Albert is analyzing carbohydrates and notices that they possess unique functions to the body. He also notices that lipids possess unique functions to the body as well. He notes that carbohydrates allow cellular respiration, energy storage, and gives structure. He also notes that Lipids allow energy storage, cell membranes, insulation and protection, and chemical messengers. What are these functions in animals and plants? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Answer: For carbohydrates, allows glucose to digest carbohydrates and can be used in cellular respiration. For carbohydrates, Energy can be stored in glycogen for humans and starch for plants. For carbohydrates, Cellulose giving strength to the Cell wall provides structure. For lipids, Energy can be stored as organisms can convert organic molecules into lipids to store energy. Phospholipids help the cell membrane and fats help protect and insulate the body. If monosaccharides can combine together to form bigger molecules, describe Dehydration synthesis and Hydrolysis. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Answer: Dehydration Synthesis removes the -OH group so that monosaccharides can bond together and form a larger compound structure. During Dehydration synthesis, water is produced as a byproduct. Compounds can be separated through hydrolysis, the -OH group is restored using a water molecule. A231 and A232 Introduction: Proteins are important for our body as they play many roles in the cell. Some of the proteins can function as enzymes, enzymes are protein catalysts that speeds up the reaction. Enzymes lower the activation energy of the chemical reaction. Enzymes acts on the reactants, the materials at the start of a reaction. The substance is called as a substrate. The enzymes bind to specific substrates. The shape of the enzyme is what makes it possible for the substrate to be specific to the enzyme. Since enzymes are proteins, they are folded into three-dimensional structures. The structures have folds or pockets on the surface, and as such, are called active sites. Active sites are the regions where the enzymes binds to the substrate. Enzymes are essentially proteins that speed up the chemical reactions, they bind to substrates with their unique structures through their active sites. (For a more detailed observation, look at the picture below) Enzymes can also be affected by conditions. Meaning, enzymes can be affected by pH levels and temperature. The reaction rate will slow down when it is not in the most optimal conditions. This occurs because enzymes are proteins. Being three dimensional structures, the conditions can disturb the enzyme’s structure. Affecting the reaction rate in general. However, this also means that enzymes can function at different conditions and temperatures optimally. Temperatures or pH levels that are too high or low denatures the enzyme. Denaturation is the process when the enzyme becomes inactive because of the many factors that alter with the structure of the enzyme. A denatured enzyme can not catalyze a reaction. If you add more substrate concentration, it does not affect the reaction rate. Increasing the concentration does not affect the enzyme’s ability to speed up the chemical reaction. However, it is limited through enzyme concentration. If there were more enzyme concentration, it would increase the chemical reaction rate. Tips for Testing:
Practice Test: Thermophilic bacteria lives in the hot springs with temperatures of 70 degrees Celsius. A group of scientists decide to collect and analyze the bacteria, how would they protect it?
Answer: B is the correct answer because since the bacteria lives in the hot springs with a temperature of 70 degrees Celsius. They would need to put it in a solution containing that optimal temperature in order to analyze the growth of it. Thomas knows that enzymes speed up chemical reactions. However, he is hypothesizing whether enzymes would slow down due to a higher concentration of substrate. If Thomas were to increase the concentration of substrate, would this affect the rate of chemical reaction?
Answer: A is correct because the amount of substrate concentration does not affect the chemical reaction, only the enzyme concentration. What is a structural feature of an enzyme?
Answer: A is the correct answer because proteins are a structural feature of an enzyme. Matthew pours the enzyme catalase in a solution of hydrogen peroxide. He notices that there are bubbles forming as the solution begins to increase rapidly, what does this mean? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Answer: The enzyme catalase is reacting with the substrate Hydrogen Peroxide. The bubbles he is noticing are the Oxygen molecules being produced as a byproduct. (Continue) After analyzing for a couple more minutes, he notices that the bubbles are slowing down, what does this mean? ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Answer: The rate of chemical reaction is slowing down as the enzyme continues to keep reacting with the Hydrogen Peroxide. The bubbles will start to slow down because the reaction is slowing down. The first thing you need to know about biochem is that
An organism is a living thing such as animals,plants ,fungi ,protist or bacteria. A cell makes up the basic unit of life, A unicellular organism such as bacteria has a Single cell to carry out all life functions. Multicellular organisms such as animals and plants may have trillions of Cells with specialized functions in that organism’s life cycle. The cells work together To carry out the organism’s function.Homeostasis is the process of maintaining a stable internal environment.But both unicellular and multicellular organisms may reproduce sexually or Asexually. Plants reproduce asexually were as animals reproduce sexually. The Plasma membrane or (Cell membrane) is a molecular bilayer that encloses a cell Next is your Cytoplasm this is the substance that fills the cell’s internal volume mostly Being water. (Remember that the liquid inside of the cell is Cytoplasm). DNA is the molecule that stores genetic information which allows the cell to pass it on To future generations Genes, ANd this Is where RNA comes into play to be copied onto Soon The RNA Is moved to the Ribosome which is the smallest organelles within the cell, You can find them all throughout the Cytoplasm, but the purpose of the Ribosome is To decode the information in the MRNA to assemble amino acids into proteins Part 2 Prokaryotic cells are unicellular organisms that lack membrane bound Organelles. Eukaryotes are much more complex they have membrane-bound organelles located within the plasma membrane. Prokaryotic cell is much smaller and simpler than a Eukaryotic cell, lacking a nucleus And other membrane bound organelles. All multicellular organisms Are Eukaryotes so all multicellular organisms have cells with nuclei and organelles. Prokaryotic Eukaryotes Nucleus No Yes Cell Number Unicellular Unicellular or multicellular DNA Circular chromosome found in cytoplasm. Linear chromosomes contained in nucleus. Examples Bacteria Plants, animals, fungi, protists Plasma membrane yes Yes Membrane-bound organelles No Yes Ribosomes Yes, small Yes, Large Cell wall Yes Present in plants and fungi Cell Diameter 1-10 micrometers(ym) 10-100 micrometers(qm)
-Cells -Atom -Ribosome 2) what is the difference between Prokaryotic and Eukaryotes
3) what does Rna do? -Help code the information from one Dna to another Dna -does RNA turn the information into proteins -does RNA than dna into proteins -can Rna go inside the ribosome 4 what are some characteristics of Prokaryotic cells that are help the body And some thing that the cell does not help with. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ 5 why is a cell the basic life unit ____________________________ ____________________________ ____________________________ ____________________________ Genes and proteins synthesis In genes and proteins synthesis you dive into learning about what Dna breaks down to In smaller componts you learn with it means for each Nucleotide to be piece of a lot of Nucleotides to make up dna. Deoxyribonucleic acid or DNA Is the molecule that stores genetic information for living things. nucleotides are made up of substances that make up DNA each nucleotide consists of a sugar a phosphate group and a nitrogen base that varies among nucleotides. These long chains of nucleotides can be consistent of 4 different nitrogen bases adenine,cytosine,thymine,guanine. Your DNA is usually found in the form of double strands made up of two molecules joined by bonds in the middle of the bases the DNA bases can bind only a specific way adenine only can bond with thymine, and cytosine can only bond with guanine The rules of this bondage is called (complementary base pairing) . Hydrogen bonds between nitrogen bases hold two Dna strands together as a double srand.A codon has a sequence of three nucleotide bases that codes for a specific amino acid In the chain. A gene can be a stretch Dna that contains the information needed to make a protein Although species differ in many of their genes, the genetic code is the same for all most. All organisms on Earth. Thus stating that there is a common origin for all life. Your chromosome is a single piece of Dna that's made up of genes. Ribonucleic acid or Rna is a single stranded nucleic Acid and contains a uracil base (U) in place of the thymine (T) found in DNa. Transcription is the process in which genetic information from Dna is copied to mRna. The sequences of junk Dna may be snipped out of an mRna transcript out of an mRna transcript by enzymes in the nucleus. (Translation from RNA to protein) A protein consists of one or more long chains of amino acids, the chains fold to Give it a three dimensional Structure. Translation is the process in which the base sequence in a strand of mRna is Converted or translated into the amino acid sequence of a protein. The ribosome of eukaryotic cells may be found free in the cytoplasm or Bound to the rough endoplasmic reticulum. rRna and proteins make up each ribosome. tRna stands for transfer Rna, because it trainsfers free amino acids to the growing peptide chain on the ribosome. An anticodon is a sequence of three tRna bases that binds to a complementary mRna codon. tRna and rRna are also transcribed from genes in the nucleus Some amino acids are coded for by more than one codon. For example histidine Is coded for by both CAUand CAC. A polypeptide is a chain of amino acids ie. a protein The order of amino acids in a protein is only one of the factors that determine the Proteins properties. Once The chain has formed, it’s folds in a specific way giving it a particular three- Dimensional shape. The shape of the protein is very important in allowing it to Function properly. Disruption to the shape of a protein can change The protein's function or make nonfunctional. Special start and stop codons on mRna tell the ribosome where translation Should begin and end . ( Protein synthesis in the cell ) The central dogma of molecular biology states that information in Dna is translated to protein. In prokaryotic cells which lack nuclei, transcription and translation to protein. In prokaryotic cells which lack nuclei transcription and translation both take place in the cytoplasm In eukaryotes ribosomes may be found either free in the cytoplasm or bound to The rough endoplasmic reticulum (ER) There are two kinds of ER rough and smooth. Smooth ER is involved in the Production of fatty acids and lipids. No ribosomes are attached to smooth ER. A vesicles from the ER to the Golgi apparatus and then to the plasma membrane. The Golgi apparatus is an organelle made up of many stacks or folds of Membrane. It accepts proteins from the ER modifies the proteins package them into vesicles on the side nearest the plasma membrane. 1) why do you think that complementary base pairing happens? - because of the number of hydrogenbonds between the two sets -because guanine and cytosine are good friends - because of the way Dna forms 2) DNA is usually found in the form of
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