Ap Bio unit 3 p2 (cellular respiration)

what do cells harvest? what do they use it for?

they harvest chemical energy in organic molecules and use it to produce ATP

what is the major source of fuel for animals? what is it broken down to?

starch, broken down to glucose

what does the oxidation of glucose transfer? What does this release?

It transfers electrons to a lower energy level which releases energy to be used in ATP synthesis

name all stages of cellular respiration

1. Glycolysis

2. Pyruvate oxidation

3. Citric acid cycle (Krebs cycle)

4. Oxidative phosphorylation (ETC and chemiosmosis)

what is glycolysis the starting point of?

cellular respiration

where does glycolysis occur?

in the cytosol

what does glycolysis split?

glucose (6C) into 2 pyruvate (3C)

how many stages are there in glycolysis? what does each entail and what are they called?

Two. Stage one is the energy investment stage where the cell uses ATP to phosphorylate compounds of glucose. Stage 2 is the energy payoff stage where energy is produced by substrate level phosphorylation.

what is the net energy yield per one glucose?

• 2 ATP

• 2 NADH

what are the starting materials and end products of glycolysis?

Starting materials- Glucose, ATP, NAD+ and ADP+P subscript i.

Final products- Pyruvate, 2 ATP, and NADH.

In pyruvate oxidation, what happens to the pyruvate if oxygen is present?

it enters a mitochondrion (eukaryotic cells)

In pyruvate oxidation, what is pyruvate oxidized into?

acetyl coA

In pyruvate oxidation, what is acetyl coA used to make?

Citrate in the citric acid cycle

In pyruvate oxidation, what is released because of the production of citrate?

CO2

In pyruvate oxidation, where are electrons transferred after citrate is produced?

to electron carriers (NADH)

what are the starting materials and end products for pyruvate oxidation?

Starting materials- Pyruvate, coenzyme A and NAD+

End products- Acetyl CoA and NADH

where does the citric acid cycle (a.k.a Krebs cycle) occur?

in the mitochondrial matrix

what does the citric acid cycle turn acetyl CoA into?

citrate

what does the citric acid cycle release?

CO2

what does the citric acid cycle synthesize?

ATP

what will NADH and FADH subscript 2 do in the citric acid cycle?

carry high energy electrons to the ETC

what are the starting materials and end products of the citric acid cycle?

Starting materials- Acetyl CoA, NAD+, FAD, and ADP+Pi

End products- CO2, NADH, FADH2, and 2 ATP

what is another name for the citric acid cycle?

the Krebs cycle

what does oxidative phosphorylation consist of?

electron transport chains and chemiosmosis

where is the ETC located?

in the inner membrane of the mitochondria

what does the ETC consist of?

Consists of a collection of electron carriers (proteins) embedded in the membrane

what brings electrons to the ETC?

NADH and FADH2 (from the krebs cycle)

what are electrons shuttled down the ETC in?

a series of redox reactions until they reach the final electron acceptor, oxygen

how do electrons move as they are transferred through the ETC?

they move from a higher to lower energy level

what is some of the released energy from electrons moving in the ETC used for?

pumping H+ into the intermembrane space, forming an electrochemical gradient of protons (H+)

where do H+ ions flow in chemiosmosis? What does this drive?

down their gradient into the matrix through ATP synthase. This drives the formation of ATP from ADP+ Pi.

what is the cristae? what does it do? what does it allow for and produce?

the cristae is the folding of the inner membrane. It increases surface area to allow for more reactions to occur, allows for more ATP to be synthesized, and produces about 26-28 ATP per glucose

what does anaerobic respiration generate?

ATP using an ETC in the absence of oxygen

where does anaerobic respiration take place?

In prokaryotic organisms that live in environments with no oxygen

what are the final electron acceptors?

sulfates or nitrates

what does fermentation generate?

ATP without an ETC

what is fermentation an extension of? Where does it occur?

glycolysis, occurs in cytosol

what does fermentation lack?

oxygen

name both types of fermentation

• Alcohol fermentation

• Lactic acid fermentation

what is pyruvate converted to in alcohol fermentation?

ethanol, e.x bacteria and yeast

what is 2 acetaldehyde converted to in alcohol fermentation

2 ethanol

What is pyruvate reduced directly by in lactic acid fermentation? What does this form?

pyruvate is reduced directly by NADH to form lactate, e.x muscle cells

what do muscles go through when they run out of oxygen? what does this cause?

lactic acid fermentation to produce ATP, this causes a burning sensation when exercising strenuously

what do muscles produce? where does this go? what is it broken down to and what organ does this take place in?

muscles produce lactate, which goes into the blood and is broken down back to glucose in the liver

what does lactate do to blood?

it lowers its pH

what can happen if lactate builds up and is unable to be broken down?

it can lead to lactic acidosis, which is excessively low pH

Study chart on the end of p55 in the workbook

Study chart on the end of p55 in the workbook