Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

37 Cards in this Set

  • Front
  • Back
3 catabolic pathways and their substrates:
-Glycolysis (glu/fructose)
-TCA (AcCoA)
-FA oxidation (FFA - mostly long chain)
What drives catabolic pathways?
Made thermodynamically favorable by concomitant reduction/oxidation.
In catabolic pathways what is:
Reduced --> NAD+
Oxidized --> Carbon molecule
What drives anabolic pathways?
In general what molecules can enter the TCA cycle? (5)
-Glucose (pyruvate metabolism)
-Fructose (pyruvate mblsm)
-Acetyl CoA (from lipids)
-Succinyl CoA (minor)
-Proteins (as amino acids)
How many reactions in the TCA cycle form CO2?
-Starting w/ glucose
-Starting w/ AcCoA
From glucose -> 3
From AcCoA -> 2
What is the ultimate worth of NADH and FADH2?
NADH = 2.5 ATP
FADH2 = 1.5 ATP
What is substrate level phosphorylation?
When an ATP or GTP is produced by a reaction directly, not from NADH/FADH2.
How does ATP provide cells with energy?
By the nature of its 2 phospate anhydride bonds.
What are the 2 phosphate anhydride bonds of ATP?
1. a-B -> gives 10.9 kcal/mol
2. B-y -> gives 7.3 kcal/mol
Which phosphate bond in ATP provides more energy? Why?
a-B -> because it releases more energy and also PPi which can be subsequently cleaved to produce energy.
What enzyme hydrolyzes PPi?
What is the typical cell conc
-of ATP
-of ADP
ATP = 3-4 mM

ADP = 0.13 mM
What is the calc for cell energy charge?
[ATP] + 1/2[ADP]
What is the typical energy charge of a cell?
0.80 - 0.95
Why do we care about cellular energy charge?
It dictates whether catabolic or anabolic processes will predominate.
What energy charge will call for catabolism?
Decreased energy charge - need energy so break things down.
What energy charge will call for anabolism?
Increased - use energy to make things.
What is the role of phosphocreatine in the body's energy stores?
When [ATP] is high and exceeds immediate needs, creatine is phosphorylated.
What is creatine?
A tissue protein especially in skeletal muscles
What happens to phosphocreatine when cell energy stores are low?
The phosphate is used to convert ADP -> ATP
What enzyme catalyzes the converstion from creatine to phosphocreatine?
Creatine phosphokinase (aka creatine kinase)
What is the specific benefit of phosphocreatine?
It provides short burts of energy for activities like weight lifting.
How many electrons are stored in NADH?
How exactly are electrons stored in NADH, and what makes them so useful?
As 2 hydride ions - they are highly energetic.
What role does NADPH have in the body?
-Antioxidant defense mechanisms
How many electrons are stored by FADH2?
One (FADH') or two (FADH2)
Why is AcCoA useful in metabolism?
It can transfer acyl or acetyl groups; contains a high energy thioester bond that makes these transfers thermodynamically favorable.
What is the body's metabolic response to high energy levels
-Store glucose as glycogen
-Store trygl. as fat
What do allosteric regulators affect?
The irreversible steps of commitment in metabolic pathways -> short term
What type of modification is:
allosteric = noncovalent

hormonal = covalent
What 2 processes control metabolism in the long term?
-Gene regulation/induction
-Protein turnover (enzyme degradation)
What is 'futile cycling'?
Simultaneous degradation and synthesis of metabolic intermediate.
What is used to prevent futile cycling?
-Tight allosteric regulation
-Compartmentalization -> keeps common intermediates separate.
List the 9 processes in the cytoplasm:
1. Cholesterol breakdown
2. FA biosynthesis
3. Tryglyc. synthesis
4. Glycolysis
5. Glycogenesis/olysis
6. HMP shunt (PPP)
7. Nucleotide synth/bkdown
8. Gluconeogenesis (part)
9. Urea cycle (part)
List the 6 processes in mitochondria:
1. TCA cycle
2. ETC/oxidative phosphoryln
3. FA oxidation
4. Urea cycle (part)
5. Gluconeogenesis (part)
6. Amino acid oxidation
What very important enzyme is in the endoplasmic reticulum?