2.5 Respiration

Question 1

significance of glycolysis

Answer 1

is the most common pathway for the catabolism of glucose; it produces energy, reduced electron carriers, and precursor molecules for cellular metabolism. Every living organism carries out some form of glycolysis, suggesting this mechanism is an ancient universal metabolic process.

Question 2

Identify the location of glycolysis in the cell.

Answer 2

Glycolysis takes place in the cytoplasm of prokaryotic and eukaryotic cells.

Question 3

Glycolytic pathways. List the three glycolytic pathways.

Answer 3

EMP, entner-doudoroff

Question 4

Summary of Entner Doudoroff Pathway

Answer 4

glucose + NADP+ + NAD+ + ADP + Pi
l
2 ethanol + NADPH + ATP

Question 5

catabolism

Answer 5

Large molecules are broken down into smaller molecules releasing energy

Question 6

The Krebs Cycle

1. Describe the first reaction in the cycle.
2. Identify the three types of reactions that occur in the cycle.
3. List the products of the cycle.
4. Explain why the cycle is important in the anabolism of the cell.

Answer 6

As one turn of the cycle returns to the starting point of the four-carbon intermediate, the cycle produces two CO2 molecules, one ATP molecule (or an equivalent, such as guanosine triphosphate [GTP]) produced by substrate-level phosphorylation, and three molecules of NADH and one of FADH2.

Question 7

Pentose-Phosphate Pathway

Answer 7

Generates NADPH and ribulose-5-phosphate

Intermediates are used for the biosynthesis of nucleotides and amino acids

Question 8

Summary of EMP Pathway

Answer 8

glucose + 2ADP + 2Pi + 2NAD+



2 pyruvate + 2ATP + 2NADH + 2H+

Question 9

Krebs Cycle

Answer 9

Used to further catabolize pyruvate into CO2
Produces many electron carriers
Produces carbon skeletons for use in biosynthesis

Question 10

Products of the Krebs Cycle

Answer 10

For each pyruvate, one molecule of CO2 and one molecule of NADH are produced in the formation of acetyl CoA.
For each acetyl-CoA molecule, the following are produced
2 molecules of CO2
3 molecules of NADH
one FADH2
one ATP
Overall Summary: two pyruvates are oxidized producing 6 CO2, 8 NADH, 2 FADH2, and 2 ATP

Question 11

Oxidative Phosphorylation

Answer 11

Electrons from the electron carriers (NADH and FADH2) are passed through the ETS
The proton gradient that is created may be used to produce ATP
From the ETS, electrons are passed to:
O2 in aerobic respiration
Other electron acceptors in anaerobic respiration

Question 12

Proton Motive Force

Answer 12

The movement of protons from the outside of the membrane into the cytoplasm can be used to:
Produce ATP
Spin flagella
Assist in nutrient transport