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129 Cards in this Set
- Front
- Back
What is metabolism?
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refers to the sum of all chemical reactions within a living organism.
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What is Anabolism?
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chemical reactions that combine simple substances into more complex molecules and requires energy
Ex. Amino acids > proteins |
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What is Catabolism?
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release energy when breaking down complex organic compounds into simpler ones
ex. Sugar > Water and Carbon Dioxide |
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Which reaction involves the expenditure of energy?
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Anabolism
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Which reaction involves the production of energy?
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Catabolism
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Are all cellular enzymes mainly composed of proteins?
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Yes.
- Most enzymes consist of both a protein portion called an apoenzyme, and a non-protein portion component called the cofactor (inorganic ion) or coenzyme (organic molecule ie. derivatives of vitamins) Some enzymes consist entirely of proteins |
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Are all cellular proteins enzymes?
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?
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What is a substrate?
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substance that enzyme specifically interacts with
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Is the substrate-enzyme interaction specific?
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Yes
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What is an apoenzyme?
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protein portion of enzyme
apoenzyme is inactive in the absence of cofactor / coenzyme |
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What is a cofactor?
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(inorganic ion)
nonprotein portion component of enzyme |
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What is a holoenzyme?
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apoenzyme+ cofactor/coenzyme
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What is a coenzyme?
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non-protein portion component of enzyme.
organic molecule ie. derivatives of vitamins |
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What is the activation energy?
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The minimum energy required to start a chemical reaction.
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How do enzymes affect the activation energy?
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they lower the amount of activation energy required.
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How does the coenzyme assist the enzyme? (3 points)
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Coenzymes assist the enzyme by:
1) accepting or donating atoms 2) donating from the substrate 3) acting as electron carriers |
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Be able to give some examples of coenzymes.
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Nicotinamide adenine dinucleotide - NAD+ : from B vitamin niacin, electron carrier
Nicotinamide adenine dinucleotide phosphate - NADP+ : from B vitamin niacin - electron carrier Flavin adenine dinucleotide: FAD : from B vitamin riboflavin coenzyme A - CoA, derivative of vitamin B pantothenic acid. |
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What is the difference between coenzymes and cofactors?
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Coenzymes are small, organic, non-protein molecules, such as vitamins, that carry chemical groups between enzymes. They are sometimes known as cosubstrates. Coenzymes are substrates for enzymes but are not considered part of an enzyme's structure.
Cofactors are non-protein chemical compounds that are bound (either tightly, as in prosthetic groups; or loosely, as in coenzymes) to an enzyme and is required for catalysis. A cofactor can be a coenzyme or a prosthetic group. |
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What metals can act as cofactors? (7)
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1. iron
2. copper 3. magnesium 4. manganese 5. zinc 6. calcium 7. cobalt |
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Describe the active site of the enzyme?
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specific region on the surface of the enzyme where the substrate contacts
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Describe the mechanism of enzymatic action. (5 steps)
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1. surface of the substrate contacts the active site of enzyme.
2. a temporary enzyme-substrate complexforms…lock key 3. substrate is transformed to products 4. enzyme and products separated 5. unchanged enzyme can then react with other substrate molecules |
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Explain how temperature affects enzymatic activity.
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An increase in temperature increases the speed of most chemical reactions
Limitation: Temperatures to high above optimal temperature will result in denaturing of enzyme and decreased chemical reactions. |
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Explain how pH affect enzymatic activity.
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Most enzymes have an optimum pH in which its activity is the maximal.
-enzymatic activity (rate of reaction) decreases above and below optimal pH -Extreme pH affect protein configuration, can cause denaturationof the enzyme. |
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Explain how substrate concentration affect enzymatic activity.
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The maximum rate of enzyme activity is attained when the substrate concentration is extremely high.
Enzyme is saturated when the enzyme's active site is always occupied by substrate. Increasing substrate concentration beyond saturation level does not increase enzymatic activity |
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What is denaturation?
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breakage of the H bonds and other noncovalent bonds that hold the enzyme in its 3-dimensional structure.
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What is the saturation point?
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when the enzyme's active site is always occupied by substrate.
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What is a competitive inhibitor?
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inhibitor competes with the normal substrate for binding to the active site of the enzyme.
It usually has similar chemical structure as the substrate. |
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What are the 4 factors influencing enzymatic activity besides conformation?
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1. Temperature
2. pH 3. Substrate Concentration 4. Inhibitors |
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What is a noncompetitive inhibitor?
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do not compete with the substrate for the enzyme's active site but may alter binding of enzyme to substrate by some other means.
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How do pharmaceutical companies take advantage of these inhibitors?
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they make all sorts of drugs that inhibit enzymes.
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How are organisms classified according to their nutritional requirement?
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Organisms can be classified metabolically according to their nutritional pattern... where they get their source of energy and source of carbon
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What is a Phototroph?
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use light as primary source of energy
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What is a Chemotroph?
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depend on oxidation-reduction reactions of inorganic or organic compounds for energy
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What is an Autotroph?
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(self feeders; aka lithotrophs): use carbon dioxide for their principal carbon source.
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What is a Heterotroph?
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(feeders on others; aka Organotrophs) : require an organic molecule for its principal carbon source.
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What are photoautotrophs?
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Use light as a source of energy and carbon dioxide as their chief source of carbon
include photosynthetic bacteria (green sulfur and purple sulfurbacteria and cyanobacteria), algae and green plants |
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Which group of organisms are photoautotrophs?
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Chlorophyll a
Bacteriochlorphylls |
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What is chlorophyll A? Which organisms use Chlorophyll A?
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Chlorophyll A is light trapping pigment used by green plants, algae, and cyanobacteria. Photoautotrophs use it.
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What organisms use bacteriochlorphyll?
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???
The light trapping pigment used by photosynthetic bacteria Bacteriochlorophylls absorb light at longer wavelengths than light absorbed by Chlorophyll A |
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What is the photosynthetic process that produces Oxygen called?
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oxygenic
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Which molecule is used to reduce carbon dioxide in oxygenic?
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H20 - Water
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What is the photosynthetic process that does not produce oxygen called?
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anoxygenic
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What organisms are anoxygenic?
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Chlorobium and Chromatium
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Which molecule is used to reduce carbon dioxide in anoxegenic?
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Sulfur, sulfur compounds, H2S (Hydrogen Sulfide)
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What are photoheterotrophs?
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use light as a source of energy and organic molecules as sources of carbon
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Be able to give examples of organic compounds/molecules that can be used as carbon sources for photoheterotrophs.
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alcohols, fatty acids, other organic acids, and carbohydrates
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What organisms are photoheterotrophs?
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Chloroflexus (green nonsulfur bacteria)
Rhodopseudomonas - purple nonsulfur bacteria |
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What are chemoautotrophs?
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-use inorganic compounds as a source of energy and use carbon dioxide as their principal source of carbon
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What are examples of inorganic molecules used? Know 3 of these.
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a. hydrogen sulfide (H2S) for Beggiatoa
b. elemental Sulfur (S) for Thiobacillus c. ammonia (NH3) for Nitrosomonas d. nitrites (NO2) for Nitrobacter; e. hydrogen gas (H2) for Hydrogenomonas; f. iron (Fe) for Thiobacillusferroxidans |
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What are chemoheterotrophs?
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-Both the energy and carbon sources are usually the same organic compound
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Which groups of organisms are considered chemoheterotrophs?
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-include a vast majority of bacteria and all fungi protozoans, and animals
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What are saprophytes?
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Chemoheterotrophs
Live on dead organic matter |
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What are parasites?
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Chemoheterotrophs
Derive nutrients from a living host. |
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Describe the oxidation-reduction reaction.
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chemical reactions in which atoms have their oxidation state changed.
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What is oxidation?
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the removal of electrons from an atom or molecule and may produce energy-
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What is reduction?
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the gain of one or more electrons by an atom or a molecule
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What does it mean if a molecule/atom is reduced? Oxidized?
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It's gained one or more electrons
It's lost an electron when oxidized. |
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What is the mechanism of ATP production?
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produced from the phosphorylationof ADP in the presence of energy provided by NADH.
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What is phosphorylation?
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the addition of Phosphate to a molecule. High energy is trapped within the covalent bond between the phosphates.
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What is carbohydrate catabolism?
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the breakdown of carbohydrates (i.e. glucose) by oxidation-reduction reaction to produce energy
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What is cellular respiration?
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Respiration is the process by which organisms burn food to produce energy. The starting material of cellular respiration is the sugar glucose, which has energy stored in its chemical bonds.
1. Glycolysis 2. Kreb'sCycle 3. Electron Transport Chain |
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What is fermentation?
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an enzymatically controlled anaerobic breakdown of an energy-rich compound (as a carbohydrate to carbon dioxide and alcohol or to an organic acid).
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What is the difference between these respiration and fermentation?
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respiration removes carbon dioxide, fermentation introduces carbon dioxide.
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What are the 3 major processes that produce ATP from carbohydrates in cellular respiration?
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Glycolysis
Kreb's Cycle Electron Transport Chain |
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What does glycolysis involve?
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oxidation of glucose to pyruvic acid + ATP + NADH<br><br>Glycolysisis the oxidation of glucose to 2 pyruvic acids.<br><br>C6H12O6 + 2ATP + 2NAD = 2pyruvate + 4ATP + 2NADH
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What are the 3 products of Glycolysis and the amount of each product from 1 glucose moleucle?
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2 Pyruvic acid
4 ATP 2 NADH |
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In Glycolysis...
Which molecule(s) get oxidized? Which molecule(s) get reduced? |
???
Oxidized: glyceraldehyde 3-phosphate (3-carbon molecule) Reduced: |
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What is the gross number of ATP molecules produced at the end of Glycolysis?
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4 ATP
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What is the net number of ATP molecules produced at the end of Glycolysis?
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2 ATP
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Explain substrate phosphorylation and when does it occur?
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The donation of a phosphate from a substrate to ADP to make ATP.
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Does glycolysis require oxygen to occur?
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No.
1. If Oxygen is not available, the pyruvic acid will form lactic acid…fermentation 2. If Oxygen isavailable, each pyruvic acid will be converted to 1 molecules of acetyl co-enzyme A, producing 1 NADH2 and 1 CO2…aerobic respiration |
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Referring to glycolysis...
Where does it occur in bacterial cells? Where does it occur in eukaryotic cells? |
-in bacteria: occur along the plasma membrane
-in eukaryotes: occur along the inner membrane of mitochondrion |
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What happens to the pyruvic acid in the intermediate step if oxygen is not present?
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If Oxygen is not available, the pyruvic acid will form lactic acid…fermentation
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What happens to the pyruvic acid in the intermediate step if oxygen is present?
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If Oxygen is available, each pyruvic acid will be converted to 1 molecules of acetyl co-enzyme A, producing 1 NADH2 and 1 CO2…aerobic respiration
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What is the Embden-Meyerhof pathway?
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Glycolysis is also called the Embden-Meyerhofpathway.
-Most microorganisms use this pathway (i.e. E.Coli,the streptococci, and most other microbial heterotrophs as well as eukaryotes) |
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What are the products of the intermediate step and the amount of each product?
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Oxygent not present: Lactic Acid
Oxygen present: 1 molecules of acetyl co-enzyme A, producing 1 NADH2 and 1 CO2 ...aerobic respiration |
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What is the major function of the Kreb's Cycle?
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Producing molecules that carry high-energy electrons to the electron transport chain
Getting rid of CO2 |
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What molecule enters the Krebs cycle?
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acetyl CoA
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What are the products of the Kreb's cycle and the amount of each product for one glucose molecule?
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2 ATP
4 CO2 6 NADH 2 FADH2 2 oxaloacetate 2acetyl-CoA + 2oxaloacetate = 4CO2 + 6NADH + 2FADH2 + 2ATP + 2oxaloacetate |
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For one acetyl CoA?
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-2 molecules of CO2-3 molecules of NADH (NicotinamideAdenine Dinucleotide)-1 molecules FADH2 (FlavinAdenine Dinucleotide)-1 molecules GTP(GuanosineTriphosphate; energy).
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Where in the bacterial cell does the Kreb's cycle occur? Where does it occur in eukaryotic cells? Be specific.
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-occurs in matrix of mitochondria in eukaryote.
-occurs in cytoplasm if prokaryote |
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Does the Kreb's cycle require oxygen to work?
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Yes it does
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What is the electron transport chain (ETC) composed of?
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The electron transport chain consists of a set of three protein pumps embedded in the inner membrane of the mitochondria. FADH2 and NADH are used to power these pumps.
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What are the 3 classes of carrier molecules (protein pumps) in ETC?
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- flavin mononucleotide (FMN)
- ubiquinones (or coenzyme Q) - cytochromes (pass electrons from one carrier to the next) |
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What is the function of electron transport chain?
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To create ATP.
By pumping H+ protons out of interstitial fluid into the intramembranous space. Protons move along energy gradient back in through ATP synthase which creates ATP. |
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Does the ETC require oxygen?
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Yes
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What is the function of oxygen in the ETC?
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Oxygen is needed in aerobic respiration in order to be the final electron acceptor
- O2 picks up electrons and protons to form water |
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Where in the bacterial cell does the ETC occur?
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Occurs along the plasma membrane
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Where does ETC occur in eukaryotic cells?
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Occurs along the inner membrane of mitochondrion
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How many ATP molecules are made from each NADH that donates its electrons to the ETC?
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3 ATP
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How many ATP molecules are made from each FADH2 that donates its electrons to the ETC?
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2 ATP
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How many ATP molecules are made from each NADH that donates its electrons to the ETC?
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3 ATP
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How many ATP molecules are made from each FADH2 that donates its electrons to the ETC?
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2 ATP
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In the presence of Oxygen, how many ATP can be made from 1 glucose molecule?
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-In prokaryotes, final amount of ATP produced: 38 -In eukaryotes, final amount of ATP molecules produced: 36
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In the absence of oxygen, how many ATP can be made from 1 glucose molecule?
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???
2 ATP |
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Explain the role of oxidation-reduction reaction in the ETC.
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NADH is oxidized, becomes NAD+ in order to recycle electron carrier for glycolysis to continue.
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Where is the proton gradient built?
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proton pumps in the mitochondrial membrane.
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Which molecule functions to generate ATP in the ETC?
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ATP synthase
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How many ATP can be made from Glycolysis and ETC?
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???
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How many ATP can be made from Intermediate step and ETC?
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???
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How many ATP molecules can be made from the Krebs cycle and ETC?
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???
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How many ATP molecules can be made from 1 glucose molecule at the end of the ETC in prokaryotes? in eukaryotes?
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In prokaryotes, final amount of ATP produced: 38 -In eukaryotes, final amount of ATP molecules produced: 36
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What is the pentose phosphate pathway and what other name is it known by?
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???
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How many ATP can be made from the pentose phosphate pathway?
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??
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What organisms use the pentose phosphate pathway?
61 |
??
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What is the Enter-Doudoroff Pathway?
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??
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How many ATP is produced from the Enter-Doudoroff pathway?
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??
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What organisms use the Enter-Doudoroff pathway?
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??
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What is fermentation?
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Fermentation is the process of deriving energy from the oxidation of organic compounds, such as carbohydrates, and using an endogenous electron
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Does fermentation require oxygen?
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No. Fermentation works in the absence of Oxygen.
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How many ATP molecules can be made from 1 glucose molecule at the end of fermentation?
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Only 1 or 2 ATP.
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What are the possible fermentation end products produced by the different organism?
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Streptococcus, Lactobacillus, Bacillus -- Lactic Acid
Saccharomyces (yeast) -- ethanol and C02 Propionibacterium -- proprionic acid, acetic acid, CO2 and H2. Clostridium -- butyric acid, butanol, acetone, isopropyl alcohol and C02. Eschericia and Salmonella -- ethanol, lactic acid, succinic acid, acetic acid, CO2, H2 Enterobacter -- ethanol, lactic acid, formic acid, butanediol, acetoin, CO2, H2. |
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Be able to give 3 examples of the organisms that undergo fermentation and all the end products that they produce from fermentation.
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Lactobacillus, Bacillus, Streptococcus -- Lactic Acid
Saccharomyces (yeast) -- Ethanol and CO2 Propionibacterium -- propionic acid, acetic acid, CO2, H2. |
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What is photosynthesis?
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The process by which photoautotrophstransform CO2and H2O into carbohydrates and O2gas using light energy
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What is the equation for photosynthesis? Be able to write out the balanced equation for photosynthesis?
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6CO2+ 12H2O ---------> C6H12O6+ 602+ 6H2O
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What is carbon fixation?
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?
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What are the 2 stages of carbon fixation?
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?
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Where does the light reaction occur in prokaryotes?
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???
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Where does the light reaction occur in eukaryotes?
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???
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Where does the dark reaction occur in prokaryotes?
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???
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Where does the dark reaction occur in eukaryotes?
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???
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What are the reactants and products of each reaction?
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???
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ATP produced during the ETC is similar to ATP produced during which step/reaction of photosynthesis?
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?
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Where is the proton gradient being built?
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?
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Which molecule is important in synthesizing ATP in photosynthesis?
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?
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How many carbon dioxide molecules are required to enter the Benson cycle to produce 1 molecule of glucose?
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?
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Which reaction in photosynthesis produces ATP? Which reaction in photosynthesis use ATP?
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?
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Photosynthesis an example of which class of metabolism?
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?
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Cellular respiration and fermentation are examples of which class of metabolism?
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?
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