bio 2 2nd exam (RESPIRATION)

Question 1

Cellular respiration

Answer 1

Cellular respiration includes both aerobic and anaerobic respiration

Question 2

NAD+

Answer 2

Reducing Agents: NAD+

Question 3

DEHYDROGENASES

Answer 3

DEHYDROGENASES- loss of hydrogen from carbon. hydrogen connects with NAD+ then is reducded, producdes NADH

Question 4

Substrate-level phosphorylation

Answer 4

Substrate-level phosphorylation- is donation of phosphate to ADP that is directly powered by making & breaking bonds.

1.Substrate level phosphorylation: the transfer of phosphate groups from ATPs to glucose​

Question 5

Oxidative Phosphorylation

Answer 5

• Oxidative Phosphorylation: powered by a proton-motive force. To make proton motive force, that typically involve electron transport.
• Establishes a PROTON MOTIVE FORCE -driving the ATPase to make ATP
• ATP is catalyzed by a proton conducting membrane-bound enzyme->ATPase (ATP synthase)
• When protons move thru ATPase, energy is captured and transferred to form ATP from ADP + P

Question 6

Aerobic Respiration

Answer 6

3 parts

1. Glycolysis
2. Krebs Cycle
3. Electron transport & Oxidative Phosphorylation

For aerobic respiration the final electron acceptor is oxygen.

the product is water

Question 7

Glycolysis(Step 1) (occurs in cytoplasm of both euk and prok)

Answer 7

• Glycolysis: is the metabolic pathway to begin breakdown of glucose
• can occur in presence or absence of oxygen, but does not require oxygen
• allows fermentation to occur but needs pyruvate
• fermentation needs glucose,

(1 glucose makes 2 pyurvate, glycolysis breaks glucose to make pyurvate)

Question 8

4 events of glycolysis

ATP being used, phosphate removed from ATP becomes ADP = starting material.

NADH goes directly to the transport chain in the mitochondira.

Answer 8

1. Substrate level phosphorylation
2. Breaking of a six-carbon molecule (glucose) into two three-carbon molecules
3. The transfer of two electrons to the coenzyme NAD (VERY IMPORTANT STEP)
4. The capture of energy in the form of ATP

flow like this glucose ->NADH ->electron transport chain->proton-motive force ATP. makes 38 ATP. forms NADH from NAD+. in glycolysis, only pyurvate enters the mitochondria, not glucose.

Question 9

To start the Krebs cycle:

Answer 9

Pyruvate loses a molecule of CO2 and is oxidized by NAD. (producdes NADH)

The resulting two-carbon acetyl group is attached to coenzyme A, forming acetyl-CoA

Krebs cycle occurs in the cytoplasm of prokaryotes & the mitochondria of eukaryotes

Question 10

Electron Transport & Oxidative Phosphorylation

Answer 10

• electron transport -membrane bound proteins that accept and donate electrons
• Electron transport takes place across the cytoplasmic membrane of prokaryotes (not have mitochondria) & across the mitochondrial membrane of eukaryotes
• Oxidative phosphorylation: energy captured is converted to high energy bonds as inorganic phosphate (Pi) combines with ADP to form ATP (accepts elecctron from NADH)

Question 11

ATP Yield for Aerobic Respiration
per molecule of glucose

Answer 11

• glycolysis: use 2 ATP
  
  • 2NADH ET/OP 3 ATP —-> 6ATP
• acetyl CoA formation
  
  • 2NADH ET/OP 3 ATP —-> 6 ATP
• Krebs cycle: use 2 ATP
  
  • 6NADH ET/OP 3 ATP —-> 18 ATP
  • 2FADH2 ET/OP 2ATP —-> 4 ATP

TOTAL 38 ATP

Question 12

Anaerobic Respiration

Answer 12

• The final electron acceptor is an inorganic molecule other than oxygen, such as:
  
  • Nitrate (N03-)
  • Sulfate (S042-)
  • Carbonate (C032-)
• Less energy is released than in aerobic respiration
• Permits microorganisms to respire in anaerobic environments
• uses electron transport chain with electron acceptor other than O2, for example sulfate.
• (fermentation uses phosporelation instead of electron xport chain to make ATP)(organism that can fermentate can live without oxygen)

Question 13

Fermentation Pathways (start with pyurvic acid) (these pathways can identify microorganisms, diseased)

Answer 13

• fermentation final electron acceptor is organic molecule
• Aerobic respfinal electron acceptor is oxygen
• Both processes use glycolysis to oxidize glucose and other organic fuels to pyruvate
• Cellular respiration make 38 ATP per glucose molecule
• fermentation make 2 ATP per glucose molecule

Question 14

Versatility of Catabolism. (remove nitrogen you have a C O H skeleton (de-ammination))

Answer 14

• Catabolic pathways funnel electrons from organic molecules into cellular respiration
• Glycolysis accepts carbohydrates
• Proteins must be digested to amino acids; amino groups can feed glycolysis or the citric acid cycle (1st step, break to amino acids)
• Get rid of nitrogen, get rid of central pathway (N) de-ammine-ate

Question 15

Protein Metabolism

Answer 15

• can get ATP through proteins!
• first hydrolyzed into individual amino acids by proteolytic enzymes
• Amino acids are deaminated
• These molecules enter glycolysis, fermentation or the Kreb’s cycle

Question 16

Fat Metabolism

Answer 16

• Most microorganisms, like most animals, can get energy from lipids
  1. Fats are hydrolyzed to glycerol and three fatty acids
  2. Glycerol is metabolized by glycolysis
  3. The fatty acids are broken down into 2-carbon pieces by beta-oxidation

Breaks down the fatty acid at 2 carbons at a time

pyurvate becoming 2 carbon then coenzyme A attaches to it.

Break molecule into glycerol backbone and the 3 fatty acids​