BIO 311C Exam 3 QUESTIONS AND ANSWERS A+ GRADED
catabolism breaks things down, anabolism is the synthesis processes, and
metabolism is the sum of all biochemical reactions in a cell
Define metabolism, anabolism and catabolism
1st law: total energy in the universe is constant and can neither be created or
destroyed
2nd law: every energy transfer or transformation results in increased randomness
(entropy) within the universe
Describe how the two laws of thermodynamics apply to biological systems
entropy (∆S) is a measure of randomness, enthalpy (∆H) is the total potential
energy or heat energy
they are related in the gibb's free energy equation by ∆G = ∆H - T∆S
Define entropy, enthalpy and free energy and give examples. How they are related to
each other in the free energy equation
exergonic (spontaneous) reaction: releases free energy (-∆G)
endergonic (non-spontaneous) reaction: absorption of free energy (+∆G)
exothermic reaction: net release of heat (-∆H)
endothermic reaction: net absorption of heat (+∆H)
define exergonic, endergonic, exothermic and endothermic reactions
energy coupling refers to the ATP needed to start and endergonic process
What is ATP and how it is used to drive endergonic processes though energy coupling
ENZYMES LOWER ACTIVATION ENERGY - THEY DO NOT CHANGE THE FREE
ENERGY
Describe enzymes and how do they help in a biochemical reaction.
describe the relationship between the enzyme active site, free energy and
activation energy changes
temperature, pH, concentration of salt and the substrate, and organic and
inorganic cofactors
what factors affecting enzyme activity and examples
competitive inhibitor: increase Km, constant Vmax
-----> inhibitor is structurally similar to substrate and binds to the active site,
preventing the actual substrate from binding
-----> can be overcome by raising substrate concentration
uncompetitive inhibitor: increased Km, decreased Vmax
----> binds to a site DIFFERENT from the active site of an enzyme AFTER the
substrate bind to the enzyme
-----> cannot be overcome by raising substrate concentration
non competitive inhibitor: lower Vmax, constant Km
-----> bind to site away from active site
-----> cannot be overcome by raising substrate concentration
, Describe substrate concentration, competitive inhibitors, non-competitive inhibitors
affect enzyme activity. How do these inhibitors affect the Vmax and Km
allosteric enzyme: can change shape depending on what binds to the (inhibitory
or activator), has multiple sites
feedback enzyme: when there is an abundance of product, enzyme 1 is inhibited
so not more product is made
How do allosteric, feedback and chemical modification regulate enzyme activity
glycolysis happens in the cytoplasm to produce pyruvate which is used in the
next step of cellular respiration, acetyl CoA formation which occurs in the
mitochondria to produce the acetyl CoA that will be used in the Kreb's Cycle (or
citric acid cycle) within the intracellular matrix to produce the essential NADH and
FADH2 that will be used in the final step of cellular respiration, oxidative
phosphorylation, which occurs within the inner membrane of the mitochondria
overview of cellular respiration
Explain how the energy stored in different types of food molecules is released in
a series of redox processes to produce ATP by substrate-level phosphorylation
and oxidative phosphorylation
where do different processes of cellular respiration occur in prokaryotic and
eukaryotic cells, and explain the role of mitochondrial structure in the such
processes
Describe how cellular respiration is regulated in cells and predict responses to
changing conditions such as lack of oxygen, relative abundance of ATP or ADP,
or specific toxins
1) glycolysis produces pyruvate that is used in acetyl CoA formation
2) acetyl CoA formation uses the pyruvate produced in glycolysis to produces
acetyl CoA that is used in the Kreb's cycle
3) the Kreb's cycle uses acetyl CoA produced in acetyl CoA formation to produce
NADH and FADH2 that will be used in oxidative phosphorylation
connect how the outputs of one process become inputs of another process of aerobic
respiration (glycolysis, acetyl CoA formation, citric acid cycle and oxidative
phosphorylation)
first committed step (step 1): glucose is phosphorylated by hexokinase
rate limiting step (step 3): phosphorylation of fructose 6-phosphate by the key
regulatory enzyme phosphofructokinase (PFK) which is activated by ADP and
AMP, and inhibited by ATP and citrate
what is the first committed step 1 and the rate-limiting step 3 in glycolysis
(inputs) C6H12O6 + 6O2 --> (outputs) 6 CO2 + 6 H2O + ATP
what are the inputs and outputs of respiration
glucose ---> 2 pyruvate + 2 H2O
2 ADP + 2 Pi ---> 2 ATP
2 NAD+ ---> 2 NADH + 2H+
what are the inputs and outputs of glycolysis
Fermentation occurs to help cells generate energy when their is a lack of oxygen.
Lactate fermentation is important for quick bursts of energy in emergency
situations
catabolism breaks things down, anabolism is the synthesis processes, and
metabolism is the sum of all biochemical reactions in a cell
Define metabolism, anabolism and catabolism
1st law: total energy in the universe is constant and can neither be created or
destroyed
2nd law: every energy transfer or transformation results in increased randomness
(entropy) within the universe
Describe how the two laws of thermodynamics apply to biological systems
entropy (∆S) is a measure of randomness, enthalpy (∆H) is the total potential
energy or heat energy
they are related in the gibb's free energy equation by ∆G = ∆H - T∆S
Define entropy, enthalpy and free energy and give examples. How they are related to
each other in the free energy equation
exergonic (spontaneous) reaction: releases free energy (-∆G)
endergonic (non-spontaneous) reaction: absorption of free energy (+∆G)
exothermic reaction: net release of heat (-∆H)
endothermic reaction: net absorption of heat (+∆H)
define exergonic, endergonic, exothermic and endothermic reactions
energy coupling refers to the ATP needed to start and endergonic process
What is ATP and how it is used to drive endergonic processes though energy coupling
ENZYMES LOWER ACTIVATION ENERGY - THEY DO NOT CHANGE THE FREE
ENERGY
Describe enzymes and how do they help in a biochemical reaction.
describe the relationship between the enzyme active site, free energy and
activation energy changes
temperature, pH, concentration of salt and the substrate, and organic and
inorganic cofactors
what factors affecting enzyme activity and examples
competitive inhibitor: increase Km, constant Vmax
-----> inhibitor is structurally similar to substrate and binds to the active site,
preventing the actual substrate from binding
-----> can be overcome by raising substrate concentration
uncompetitive inhibitor: increased Km, decreased Vmax
----> binds to a site DIFFERENT from the active site of an enzyme AFTER the
substrate bind to the enzyme
-----> cannot be overcome by raising substrate concentration
non competitive inhibitor: lower Vmax, constant Km
-----> bind to site away from active site
-----> cannot be overcome by raising substrate concentration
, Describe substrate concentration, competitive inhibitors, non-competitive inhibitors
affect enzyme activity. How do these inhibitors affect the Vmax and Km
allosteric enzyme: can change shape depending on what binds to the (inhibitory
or activator), has multiple sites
feedback enzyme: when there is an abundance of product, enzyme 1 is inhibited
so not more product is made
How do allosteric, feedback and chemical modification regulate enzyme activity
glycolysis happens in the cytoplasm to produce pyruvate which is used in the
next step of cellular respiration, acetyl CoA formation which occurs in the
mitochondria to produce the acetyl CoA that will be used in the Kreb's Cycle (or
citric acid cycle) within the intracellular matrix to produce the essential NADH and
FADH2 that will be used in the final step of cellular respiration, oxidative
phosphorylation, which occurs within the inner membrane of the mitochondria
overview of cellular respiration
Explain how the energy stored in different types of food molecules is released in
a series of redox processes to produce ATP by substrate-level phosphorylation
and oxidative phosphorylation
where do different processes of cellular respiration occur in prokaryotic and
eukaryotic cells, and explain the role of mitochondrial structure in the such
processes
Describe how cellular respiration is regulated in cells and predict responses to
changing conditions such as lack of oxygen, relative abundance of ATP or ADP,
or specific toxins
1) glycolysis produces pyruvate that is used in acetyl CoA formation
2) acetyl CoA formation uses the pyruvate produced in glycolysis to produces
acetyl CoA that is used in the Kreb's cycle
3) the Kreb's cycle uses acetyl CoA produced in acetyl CoA formation to produce
NADH and FADH2 that will be used in oxidative phosphorylation
connect how the outputs of one process become inputs of another process of aerobic
respiration (glycolysis, acetyl CoA formation, citric acid cycle and oxidative
phosphorylation)
first committed step (step 1): glucose is phosphorylated by hexokinase
rate limiting step (step 3): phosphorylation of fructose 6-phosphate by the key
regulatory enzyme phosphofructokinase (PFK) which is activated by ADP and
AMP, and inhibited by ATP and citrate
what is the first committed step 1 and the rate-limiting step 3 in glycolysis
(inputs) C6H12O6 + 6O2 --> (outputs) 6 CO2 + 6 H2O + ATP
what are the inputs and outputs of respiration
glucose ---> 2 pyruvate + 2 H2O
2 ADP + 2 Pi ---> 2 ATP
2 NAD+ ---> 2 NADH + 2H+
what are the inputs and outputs of glycolysis
Fermentation occurs to help cells generate energy when their is a lack of oxygen.
Lactate fermentation is important for quick bursts of energy in emergency
situations
