Biology 2E Chapter 7 Cellular Respiration

Flashcards for Biology 2E Chapter 7: Cellular Respiration

Redox Reactions

Chemical reactions where electrons are transferred from one molecule to another.

Reducing Agents

Molecules that can donate electron(s) in a redox reaction.

Oxidizing Agents

Molecules that can accept electrons in a redox reaction.

NADH

Molecule that carries 2e- and 1H+ more than NAD+.

NAD+

Molecule that accepts electrons from redox reactions while NADH donates them.

Dephosphorylation

The loss of a phosphate group from a molecule.

Phosphorylation

The process of adding a phosphate group to a molecule.

Phosphorylation

ATP is generated by an endergonic reaction where ADP undergoes this.

ATP synthase

Enzyme required for chemiosmosis.

Glycolysis

First metabolic pathway of glucose metabolism.

Cytoplasm

Location of glycolysis.

2 Pyruvate, 2 NADH, 4 ATP, 2 ADP

Products of glycolysis.

2 ATP

Net ATP production of glycolysis.

Substrate-level phosphorylation

ATP is formed in glycolysis by this process.

Acetyl CoA

Molecule that pyruvate is converted to in the mitochondria.

2 pyruvate, 2 NAD+, 2 coenzyme A

Inputs of pyruvate oxidation.

2 CO2, 2 NADH, 2 acetyl CoA

Outputs of pyruvate oxidation.

Mitochondrial matrix

Location of the citric acid cycle in eukaryotes.

Oxaloacetate

The acetyl group from acetyl CoA is transferred to this molecule in the citric acid cycle.

Citrate

The first product formed when acetyl CoA is transferred to oxaloacetate.

3 NADH, 1 FADH2, 1 ATP

Products of Citric Acid Cycle (from each pyruvate).

4 ATP

Total ATP produced by substrate-level phosphorylation by the end of CAC.

6 CO2

Total amount of CO2 produced by the end of the CAC.

10 NADH

Total amount of NADH produced by the end of CAC.

2 FADH2

Total amount of FADH2 produced by the end of CAC.

Oxidative phosphorylation

Process that uses NADH and FADH2 to form ATP in the mitochondrion.

Oxidative phosphorylation

Only pathway in cellular respiration where O2 is an input.

Chemiosmosis

The electron transport chain and this process generate ATP.

Electron transport chain (ETC)

Series of electron transporters embedded in the inner mitochondrial membrane.

Intermembrane space

Protons are pumped from the mitochondrial matrix to this location.

O2

Molecule that is reduced to form H2O in the ETC.

Complex I

e- from NADH are transferred to this complex in the ETC.

Complex II

e- from FADH2 enter the ETC at this complex.

Cytochrome oxidoreductase

Complex III in the ETC is also known as this.

Cytochrome C

Molecule that carries each e- to complex IV in the ETC.

Oxygen

Final electron acceptor in the ETC.

ADP + Pi

Chemiosmosis uses kinetic energy from protons falling down its gradient to form ATP from these molecules.

ATP synthase

Complex, integral protein that mediates chemiosmosis.

32-34

The net ATP yield from chemiosmosis per glucose.

32-34 ATP

This ATP is formed by oxidative phosphorylation.

4

The net ATP yield from glycolysis and CAC.

36-38

The total ATP yield from the overall process of cellular respiration.

Glycolysis

Process that regenerates NAD+ during oxidative phosphorylation when O2 is present.

Anaerobic respiration

In this process, the final electron acceptor is an inorganic molecule, rather than oxygen.

Fermentation

This is a different process than anaerobic respiration because it only involves glycolysis.

Lactic acid fermentation & Alcohol fermentation

Two common types of fermentation.

Lactic acid fermentation

Type of fermentation that occurs in muscle cells when O2 is limited.

Lactate dehydrogenase

Enzyme that catalyzes lactic acid fermentation.

Anaerobic yeast species

Organisms that can perform alcohol fermentation.

Glycolysis or the CAC pathways

Catabolic pathways for carbohydrates, lipids, and proteins eventually connect to these.

Hormonal control, enzyme reversibility, enzyme sensitivity to pH changes, feedback controls

Cellular respiration is regulated by these mechanisms.

Insulin

In the presence of this hormone, Glut4 vesicles fuse with the plasma membrane.

Glut4

Molecule that allows glucose to enter the cell.

Electron Carrier

Electron carrier important in both cellular respiration and photosynthesis.

Cellular Respiration

Molecule consisting of glucose + 6 oxygen producing 6 carbon dioxide + 6 water + ~36 ATP

NAD+

Molecule like NAD (nicotinamide adenine dinucleotide) that can occur in an oxidized state .

Glycolysis, Oxidation of Pyruvate and Citric Acid Cycle, Oxidative Phosphorylation

The metabolic pathways cellular respiration includes.

NADH

Molecule in the second half of glycolysis that involves phosphorylation without ATP investment (step 6) and produces two NADH and four ATP molecules to generate 2 pyruvate molecules.

substrate-level phosphorylation

Occurs when ATP is formed in glycolysis meaning that the phosphate group comes from a reactant molecule (i.e., the substrate), rather than an unattached inorganic phosphate.

Oxidation of Pyruvate

Occurs in eukaryotic cells, if oxygen is present, the 2 pyruvate molecules enter mitochondria where each is converted to Acetyl CoA before entering the citric acid cycle (CAC).

electron transporters

The electron transport chain (ETC) is a series of these embedded in the inner mitochondrial membrane.

inner mitochondrial membrane

Embedded location of shuttle electrons from NADH and FADH2 to O2.

NADH and FADH2 to O2

In the electron transport chain (ETC), they shuttle electrons from this molecule.

Pyruvate + NADH → lactate + NAD+

It results in lactic acid fermentation.

Pyruvate + NADH → ethanol + CO2 + NAD+

It results in alcohol fermentation.

Enzyme affected Elevated levels of effector

These controls affect regulatory mechanisms.

Cellular Respiration

Chemical process where cells extract energy from food to generate ATP.

Nicotinamide adenine dinucleotide

Molecule that can be either oxidized (NAD+) or reduced (NADH).

Enzyme Irreversibility

Occurs when an enzyme is able to exceed equilibrium.

Oxaloacetate

The product of the citric acid cycle.

substrate-level phosphorylation

Occurs when an unattached inorganic phosphate binds to ADP to produce ATP during glycolysis.

ATP

Oxidative phosphorylation uses NADH and FADH2 from previous steps to form this.

Fermentation

Process where some organisms can regenerate NAD+ in the absence of oxygen, otherwise, glycolysis would halt.

Incremental Transfer

Occurs when the cell transfers food energy in small packages that can be captured in the phosphate bonds of ATP.

Pyruvate

Is the product of Glycolysis

Cytochrome C

Carries each e- to complex IV

Oxaloacetate

First, the acetyl group from acetyl CoA is transferred to this in Citric Acid Cycle.