Chapter 9? Carb Metabolism Flashcards
Glycogen is the most abundant:
Animal carbohydrate
Glucose oxidation provides _____ at _____/______ capable of supporting a wide variety of activities.
ATP, Rates, Quantities
The most abundant animal carb is:
Glycogen
On average a 154 lb man has how much glycogen stored?
15.5 ounces
Glycogen stored in the muscles and liver in the:
Cytosol
The glycogen in the cytosol is kept in:
Granules
The granules contain:
The enzyme that controls synthesis/breakdown as well as enzymes that regulate the process
UDP-glucose is the:
Activated form of glucose
The activated form of glucose is called:
UDP-glucose
Glycogen synthesis makes only:
α1-4 bonds
Branching enzyme makes:
Branching enzyme breaks:
α1-6 bonds
α1-4 bonds
How many enzymes build glycogen?
Two
How many enzymes are involved in breaking down glycogen?
Two
What breaks α1-4 linkages while transferring phosphates to liberated glucose molecules?
Phosphorylase
What is the purpose of phosphorylase?
To break α1-4 linkages while transferring phosphates to liberated glucose molecules
Phosphorylase is unable to:
Remove glucose residues from a branch point
Debranching enzyme:
Catalyzes two reactions
Debating enzyme catalyzes two reactions:
- Transport of remaining glucosyl units of a branch to the end of another branch.
- Removes the remaining glucosyl unit by hydrolysis of the α1-6 bond
Phosphorylase a is:
Active
Phosphorylase b is:
Inactive but can be active
Transitioning from phosphorylase a to phosphorylase b is done by:
Protein Phosphatase 1
(PP1)
Transitioning from phosphorylase b to phosphorylase a is done by:
Phosphorylase kinase
Protein Phosphatase 1 removes phosphates from:
Active Phosphorylase
Glycogenolysis rates are ____ in resting muscle.
Low
What makes only α1-4 bonds?
Glycogen synthase
What are the glycogenolysis rates in resting muscle?
Low
What activates glycogenolysis during exercise?
Epinephrine and glucagon
What happens to Pi concentrations during exercise?
Increase
What enzyme is inhibited by protein phosphatase I?
Phosphorylase b
What is the form of phosphorylase when it is inactive?
Phosphorylase b
What process leads to the activation of phosphorylase?
Phosphorylation by phosphorylase kinase
What inhibits phosphorylase activity?
ATP
What happens to AMP and IMP during exercise?
They increase
What happens to ATP levels during exercise?
Decrease
What role does AMP have in relation to phosphorylase?
Allosteric activator
True or False: ATP acts as an allosteric inhibitor of phosphorylase.
True
What activates phosphorylase kinase?
Calcium activates phosphorylase kinase
Calcium plays a critical role in the activation of phosphorylase kinase, which is important for glycogenolysis.
How does exercise affect calcium signaling?
Exercise increases calcium signaling
The intensity of exercise can influence the levels of calcium in muscle cells, impacting various metabolic pathways.
Where is epinephrine released from?
Epinephrine is released from the adrenal medulla
The adrenal medulla is part of the adrenal glands and plays a key role in the body’s fight-or-flight response.
What is the relationship between exercise intensity and epinephrine release?
More intense exercise leads to more epinephrine release
Higher exercise intensity triggers greater physiological responses, including increased secretion of epinephrine.
Fill in the blank: _______ is released from the adrenal medulla.
Epinephrine
What type of receptors does epinephrine bind to in muscle?
B-adrenergic receptors
What is the role of adenylate cyclase in the signaling pathway activated by epinephrine?
Converts ATP to cyclic-AMP (cAMP)
What is the reaction catalyzed by adenylate cyclase?
ATP → cAMP + PPi
What is the Gibbs free energy change (AG°’) for the reaction involving adenylate cyclase?
1.6 kcal/mol
What metabolic process is activated as a result of the signaling pathway initiated by epinephrine?
Glycogenolysis
Fill in the blank: In muscle, epinephrine binds to _______.
B-adrenergic receptors
Epinephrine binds to:
β-adrenergic receptors
When epinephrine binds to β-Adrenergic receptors what is produced?
cAMP
The most common energy pathway is:
Glycolysis
The sole source of energy for erythrocytes is:
Glycolysis
Glucose 1-phosphate interacts with ____ to make glucose 6-phosphate.
Phosphoglucomutase
Glucose is phosphorylated by:
Hexokinase
When glucose interacts with hexokinase ______ is produced.
Glucose 6-phosphate
Glucose 6-phosphate interacts with ______.
Phosphohexoisomerase
Glucose 6-phosphate interacts with phosphohexoseisomerase to produce:
Fructose 6-phosphate
Fructose 6-phosphate interacts with phosphofructokinase to produce:
Fructose 1,6-biphosphate
