Energy Metabolism

NEUR 2025 Exam 2

A large percentage of the body’s ATP is consumed by what cellular process?

pumping Na/K pump

ATP structure

3 phosphate groups, ribose, adenine

What are the bonds between the phosphorous and oxygen atoms (between phosphate groups) of the ATP molecule?

phosphoanhydride bonds

Why do phosphoanydride bonds store so much energy?

phosphate groups are negatively charged and repel each other

From closest to furthest from the ribose, what are the phosphate groups called?

alpha, beta, gamma

What reaction occurs to remove a phosphate group from ATP?

hydrolysis reaction

Product of ATP hydrolysis

ADP; adenosine diphosphate

Product of ADP hydrolysis

AMP; adenosine monophosphate

What is the ETC also known as?

oxidative phosphorylation

What important molecules do glycolysis and the Krebs cycle yield to be used in ETC?

NADH, FADH2

Which molecule enters the Krebs cycle?

pyruvate

What processes other than glycolysis can produce reactants for the Krebs cycle?

lipid and protein catabolism

Glycolysis (simple)

1 glucose converted into 2 pyruvate

net 2 ATP, 2 NADH

Glucose gets converted into what molecule (intermediate 1)?

glucose-6-phosphate

What does glucose-6-phosphate get converted into?

fructose-6-phosphate

What does fructose-6-phosphate get converted into?

fructose-1,6-biphosphate

What does fructose-1,6-biphosphate get converted into?

2 molecules of glyceraldehyde-3-phosphate

What does glyceraldehyde-3-phosphate get converted into?

1,3-bisphosphoglycerate

When does NAD+ get reduced to NADH during glycolysis?

When glyceraldehyde-3-phosphate gets converted into 1,3-bisphosphoglycerate

Oxidation means you’re doing what to electrons?

losing them (fewer electrons)

Reduction means you’re doing what to electrons?

gaining them (more electrons)

What does 1,3-bisphosphoglycerate get converted into?

3-phosphglycerate

When does ATP get made during glycolysis?

• when 1,3-bisphosphoglycerate gets turned into 3-phosphoglycerate

• when phosphoenolpyruvate gets turned into pyruvate

• (phosphorylating ADP to make ATP)

What does 3-phosphoglycerate get converted into?

2-phosphoglycerate

What does 2-phosphoglycerate get converted into?

phosphoenolpyruvate

What does phosphoenolpyruvate get converted into?

pyruvate

Before entering the Krebs cycle, what does pyruvate (from Glycolysis) get oxidized into?

acetyl-CoA

What also happens when pyruvate gets oxidized?

• NAD+ is reduced to NADH (w/ a leftover proton)

• CO2 produced (when pyruvic acid loses a carbon)

What is a coenzyme?

non-protein compound that’s necessary for the functioning of an enzyme

What molecule is used to convert pyruvate into acetyl CoA

coenzyme A