Cell Biology Lecture 17 - Energy from Food

Vocabulary flashcards based on Cell Biology Lecture Notes (from ppt).

Carbohydrate Breakdown

The breakdown of carbohydrates, particularly glucose, is a major source of cellular energy.

How much energy does glucose breakdown yield?

The complete breakdown of glucose to CO2 and H20 yields lots of free energy: ∆G = -686 kcal/mol

Glycolysis

The initial process in the breakdown of glucose, common to virtually all cells.

What is NAD+ to NADH conversion?

Glycolysis converts two molecules of the coenzyme NAD+ to NADH.

Where does glycolysis take place?

Cytosol

What is a process that does not require oxygen (ex. glucose) called?

anaerobic process

Phosphofructokinase

Key control point in the glycolytic pathway.

How much energy does glycolysis consume?

Requires 2 molecules of ATP per molecule of glucose

How is ATP formed from ADP?

Phosphorylation - when a phosphate group is added to ADP, creating a high-energy bond.

What is the net ATP gain of glycolysis?

2 ATP molecules (2 consumed, 4 made = 2)

Citric Acid Cycle (Krebs Cycle)

The central pathway in oxidative metabolism.

What does pyruvate need to be converted to first before use in the citric acid cycle?

Acetyl-CoA

Coenzyme A (CoA)

Serves as a carrier of acyl groups in various metabolic reactions.

Where does oxidative phosphorylation occur?

Mitochondrial membrane

Oxidative Phosphorylation

Process of electron transport where electrons donated from NADH and FADH2 combine with O2 releasing energy.

How much ATP do NADH and FADH₂ produce?

Each NADH produces 3 ATP and each FADH₂ produces 2 ATP.

Citric Acid Cycle Products

Net products are 6 NADH, 2 FADH2, and 2 GTP

ATP Yield from Fatty Acids

A 16-carbon fatty acid yields 130 molecules of ATP.