Ap Bio- Aerobic Cellular Respiration

Aerobic cellular respiration

Utilization of oxygen to burn glucose for the release of energy. Occurs in the mitochondria, requires O2 and releases energy (38 ATP total)

After glycolysis if what is present may 2 pyruvates enter the mitochondria

O2

what else must enter mitochondrion?

2 NADH from glycolysis

During formation of acetyl CoA, what is oxidized?

pyruvate

Coenzyme A binds with each acetate, resulting in?

2 Acetyl CoA

What is released during formation of acetyl CoA

2 Co2 released as waste

2 NAD+ is reduced as what?

2 NADH

During Krebs cycle, what is oxidized?

acetate molecules

more and more of the energy during the Krebs cycle is pushed out from what original molecule?

Glucose

During Krebs cycle, what is released as waste during per turn of cycle?

2 Co2

What else is generated per turn during Krebs Cycle?

1 ATP, 3 NADHs, and 1 FADH2

4 phases for cellular respiration

1. Glycolysis - energy in glucose generates ATP and NADH, end product: pyruvate/pyruvic acid (3c)

2. Link Reaction - brings pyruvic acid into mitochondria, converts it to acetyl CoA, generates NADH, releases 1 Co2

3. Krebs Cycle- oxidizes acetyl CoA to produce 3 NADH, 1 ATP, and 1 FADH2; releases 2 Co2s

4. Electron transport chain-oxidizes NADH and FADH2 to create electron flow which powers chemiosmotic phosphorylation of ADP--> ATP

What happens during glycolysis?

1 molecule of glucose, a 6-carbon compound, is transformed into 2 molecules of pyruvic acid, a 3-carbon compound

3 phases in glycolysis

1. phosphorylation of glucose

2. splitting/ cleavage of glucose into 2 3- carbon molecules

3. production of NADH, ATP, and 2 molecules of pyruvic acid

What happens during glycolysis and Krebs cycle?

the Link reaction. Enzymes removes Co2 from pyruvic acid, 1/3 of Co2 is released during c. respiration, other enzymes oxidize 2 Co2 into an acetyl group, acetyl oxidization, electrons lost during previous step go into NAD+ reduced to NADH which has energy that can be used, enzymes take acetyl group and attach CoA, boom acetyl CoA

Describe Krebs Cycle

Acetyl CoA combines with a 6C molecule, release 2 molecules of CO2, 3 molecules of NADH, 1 molecule of FADH and 1 molecule of ATP to form a 4 carbon molecule which then transforms back into acetyl CoA. (For each acetyl CoA that enters), oxaloacetate is the ending and starting compound.

In depth Krebs Cycle

enzymes transfer the (2c) acetyl group from acetyl CoA ---> oxalic acid (4c) ---> 6c Citric Acid, enzymes oxidize citric acid, its electrons are used to reduce NAD+ and FAD to NADH and FADH2, (go up for the last parts), other enzymes power a substrate level phosphorylation of ADP + P = ATP

Explain how mitochondrial electron transport chain generates ATP

-electrons from NADH and FADH2 are oxidized

• electrons flow through electron transport chain, a series of membrane embedded proteins in the mitochondrial matrix

• Some of the ETC proteins are protein pumps that pump protons from the matrix to the intermembrane space, creating electrochemical gradient

• O2 acts as the final electron acceptor "pulling" electrons down etc..., increasing the proton gradient between matrix and intermembrane space

• facilitated diffusion through ATP Synthase channel back to matrix, powers formation of ATP from ADP + P

Chemiosmosis

ATP Synthase through facilitated diffusion of protons

What other sources of energy can be oxidized for energy in c. respiration?

carbs, proteins, fats

Carbs used in c. respiration

starch (bread, potatoes, pasta) and glycogen (stored in liver and muscles) = glucose

• disaccharides and monosaccharides from food = glucose

• w/ glucose, simply start in glycolysis

Proteins used in c. respiration

proteins --> amino acids (digestion)

• most aa used to build new proteins

• deamination = amino group removed which creates ammonia/urea --> urine

• 2c amino acids --> acetate (krebs)

• 3c amino acids --> pyruvate (formation of acetyl CoA)

Fats used in c. respiration

• fats broken down into glycerol and fatty acids

• glycerol ---> G3P (2nd half of glycolysis)

• fatty acids are "chopped up" into 2c fragments = beta oxidization

• each 2c fragments --> acetate (Krebs)

• up to 48 acetate molecules can be made from a single molecule of fat

• up to 504 ATPs after Krebs/etc!!