BIO 141 - ch 9 - cellular respiration

Both catabolic [break down] pathway of making ATP

Fermentation

• its a partial degradation of sugars that occurs without oxygen

Cellular respiration

• includes both aerobic and anaerobic respiration

• the break down of glucose and other organic molecules to produce ATP

• aerobic respiration yields significantly more ATP using an ETC and oxygen as the final electron acceptor.

Distinguish between fermentation and cellular respiration.

• what is the reactants and products of glucose

glucose + oxygen = CO2 + water + ATP [heat]

when oxygen is added to glucose it is able to break down. its products are CO2, water, ATP, and heat

Glucose releases energy when its bonds are broken.

Describe the summary equation for cellular respiration.

Also note the specific chemical equation for the degradation of glucose

ATP can go through hydrolysis [add water] and break down to ADP plus P

and go through cellular processes to regenerate ATP

Explain how ATP is recycled in cells.

loss of electrons = oxidation

addition of electrons = reduction

oxidation-reduction reactions = redox

Define oxidation and reduction

define redox reaction

glucose and other organic molecules are oxidized in a series of steps

each electron travels with a proton - thus as a hydrogen atom

hydrogen atoms are usually first passed to electron carriers than directly to O2

Explain why organic molecules that have an abundance of hydrogen are excellent cellular fuels.

NADplus can be reduced into NADH.

ETC accepts electrons from NADH and FADH2 and passes them through a series of protein complexes to lower energy states, ultimitly reaching oxygen. this electron flow powers the pumping of protons to establish a proton gradient

Describe the role of NAD+ and the electron transport chain during respiration

glycolysis - cytoplasm

krebs - mitochondrial matrix

ETC - inner membrane of mitochondrion

Describe the cellular regions where glycolysis, the Krebs cycle, and the electron transport chain occur

ATP is needed to break down glucose into 2 pyruvates - which starts the glycolysis stage

Explain why ATP is required for the preparatory steps of glycolysis

in glycolysis

• the oxidation and reduction of NADplus to NADH occur during their energy payoff phase

• substrate phosphorylation also occurs in the payoff phase when enzymes transfer phosphate groups directly from ADP to ADP

pyruvate to acetyl CoA

• pyruvate is oxidized as it enters into the mitochondrion, producing CO2, NADH, and acetyl CoA

Krebs link

• the transition converts the end product of glycolysis - pyruvate - into acetyl CoA, which the directly enters and dives the krebs cycle

Identify where sugar oxidation, substrate-level phosphorylation, and the reduction of NAD+ occur in glycolysis,

where pyruvate is oxidized to acetyl CoA,

what molecules are produced,

and how this process links glycolysis to the Krebs cycle

as electrons exergonically move doen the ETC free energy is released and used by protein complexes to pump protons [H] across the membrane.

this creates a proton gradident that couples the rel

Explain how the exergonic "slide" of electrons down the electron transport chain is coupled to the endergonic production of ATP by chemiosmosis

chemiosmosis is the process where protons flow down their concentration gradient back into the mitochondrial matrix using ATP synthase.

the flow of protons turns the ADP back into ATP

Describe the process of chemiosmosis

protein

• broken down into amino acids, remove amino groups as NH3, enter glycolysis, pyruvate oxidation, or CAC

carb

• concerted into sugars that feed directly into glycolysis

fat

• broken down into glycerol - which can enter glycolysis - and fatty acids - which can be broken down into acetyl CoA and enter CAC

Describe how food molecules other than glucose can be oxidized to make ATP

ATP is controlled via feedback regulation

PFK is an allosteric enzyme that acts as the pacemaker of glycolysis

where there is an abundance of ATP it can inhibit PFK by binding to it. when this happens glycolysis and cellular respiration is slowed

once ATP levels drop the inhibition is lifted and the cycle can continue

Explain how ATP production is controlled by the cell and what role the allosteric enzyme, phosphofructokinase, plays in the process

stage - 1 - glycolysis

location - cytoplasm

energy in - glucose bonds, 2ATP [ a little ATP]

energy out - 2 pyruvate bonds, NADH, ATP

brief description- glucose is stable and something has to destabilize it. adding ATP adding phosphate destabilizes it and breaks it down enough to make energy. it is a rearrangement of molecules [carbons] - which releases a little bit of NADH, and a little ATP then your up to pyruvate

Glycolysis

• stage

• location

• energy in

• energy out

• brief description