Respiration/fermentation ch8/9

aerobic respiration

I biochemical reaction using O2 and an organic compound (often glucose) to make cellular energy

is respiration exergonic or endergonic

I exergonic

is photosynthesis exergonic or endergonic

I endergonic

chemical equation for cellular respiration

I C6H12O6 + 6O2

does C6H12O6 or 6CO2 + 6H2O have more energy

I C6H12O6

breathing

I mechanical action of lungs, ribcage, and diaphragm to bring air (O2) into our bodies

how does the 2nd law of thermo apply to cellular respiration

I not all glucose in our bodies is turned into mechanical energy; much is lost as heat

redox reactions

I transfer of e

oxidation

I loss of e

reduction

I gain of e

do redox reactions happen by itself or in pairs?

I in pairs: one chemical is reduced and the other is oxidized

in respiration, what is reduced and what is oxidized?

I glucose is oxidized to form CO2
oxygen is reduced to form H2O

why does glucose not immediately oxidize?

I glucose has a high energy of activation so it requires an input of heat or more enzymes for the reaction to proceed

what are the 3 steps of cellular respiration?

I 1. Glycolysis

2. Krebs Cycle
3. Electron Transport Chain

glycolysis

I the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

where does glycolysis occur

I cytosol

end product of glycolysis

I 2 pyruvate (c3h3o3), 2 NADH, 2 ATP

glycolysis chemical equation

I c6h12o6 + 2NAD+ + 2 ATP

how many ATP's are used in glycolysis?
how many ATP's are gained in glycolysis?
what is the net ATP release after glycolysis

I 2 ATP used
4 ATP released
net gain: 2 ATP

NAD+/NADH

I an organic molecule that serves as an electron carrier by being oxidized (losing electrons) to NAD+ and reduced (gaining electrons) to NADH

pyruvate decarboxylation

I pyruvate converted to acetyl CoA

where does pyruvate decarboxylation occur

I mitochondrial matrix

chemical equation for pyruvate decarboxylation

I 2 pyruvate + 2 coenzyme A + 2NAD+

what happens with each of the products of pyruvate decarboxylation

I co2: a byproduct
acetyl CoA: continues to citric acid cycle
NADH: goes to phosphorylation

when was the citric acid cycle discovered?

I 1930s

where does the citric acid occur in eukaryotes

I mitochondrial matrix

where does the citric acid occur in prokaryotes

I cytosol

at what step does acetyl coA get oxidized

I citric acid cycle: oxidized acetyl coA to CO2

what is the energy source for the krebs cycle

I acetyl coA

what does acetyl coA bind with at the start of the krebs cycle?
what does this form?

I oxaloacetate
this forms citrate

after 8 enzyme catalyzed steps, 2 acetyl coA produce a NET gain of …

I 2 ATP
6 NADH
2 FADH
4 CO2

2 parts of oxidative phosphorylation

I 1. electron transport chain

2. chemiosmosis

where does the e

transport chain occur in eukaryotes

where does the e

transport chain occur in prokaryotes

importance of e

carriers to e

what is the energy source for oxidative phosphorylation

I NADH and FADH2

what a protein accepts an e

, does it become oxidized or reduced?

what are e

used for at the end of the e

importance of step down process

I releases small bursts of usable energy instead of 1 big burst of energy

chemiosmosis

I Process by which a Hydrogen pump pumps protons into the thylakoid membrane

Where does chemiosmosis occur?

I inner mitochondrial membrane

when is H2 released in chemiosmosis

I h2 is released when NADH and FADH2 are oxidized

how does h2 return to the mitochondrial matrix in chemoismosis

I ATP synthase

how does the atp synthase work (rotor, stator, rod, knob)

I Rotor: embedded in the membrane and spins as protons flow through it, driven by the proton gradient.
Stator: stationary part that holds the catalytic knob in place and prevents it from spinning with the rotor.
Rod: The rod connects the rotor to the knob and spins inside the knob as the rotor turns.
Knob: Located inside the mitochondrial matrix (or cytoplasm in prokaryotes), the knob contains the active sites where ADP and inorganic phosphate combine to form ATP. The rotation of the rod induces conformational changes in the knob, driving ATP synthesis.

one molecule of glucose produces

I 30

in oxidative phosphorylation, does the mitochondrial matrix or intermembrane space have more protons

I intermembrane space

(e

transport chain) what happens at the first membrane protein

(e

transport chain) what happens at the second membrane protein

(e

transport chain) what happens at the third membrane protein

(e

transport chain) what happens at the fourth membrane protein

how does cyanide work

I it binds to the mitochondrial enzyme that is necessary for ATP production; the person becomes anaerobic, effecting the brain and heart causing death

how do plant pesticides work

I poke holes in cell membrane

why is there a difference in ATP yield (like why is it 30

32 ATP and not a certain number)

Fermentation

I no O2, no e

where does alcohol fermentation occur

I in yeast (fungi) and some bacteria

process of alcohol fermentation

I pyruvates and NADHs oxidized; breaks into acetaldehyde and CO2; the acetaldehyde breaks into 2 ethyl alcohol

net gain in alcohol fermentation

I 2 ATP

where in the cell does alcohol fermentation occur

I cytoplasm

ethanol production oxidizes ____ to _____

I NADH to NAH+

where does lactic acid fermentation occur

I bacteria, fungi, or animals

why does lactic acid fermentation occur in human muscle cells

I an alternative to aerobic respiration if oxygen is not available

what happens in lactic acid fermentation

I pyruvate is reduced by NADH, forming lactate as an end product, with no release of CO2

net gain in lactic acid fermentation

I 2 ATP

lacate formation oxidizes ____ to ____

I NADH to NAD+

how is lactic acid fermentation different from alcohol fermentation

I in lactic acid fermentation, pyruvate isn't being broken down into subunits and then used to form end product

cori cycle

I Lactate conversion to glucose in the liver.

how are other carbs transformed for energy use?

work like glucose so glycolysis--> krebs cycle--> ETC

how are lipids transformed for energy use?

1. glycerol backbone becomes glucose like substance; behaves like glucose so glycolysis--> krebs cycle--> ETC

2. fatty acids--> acetyl coA--> krebs cycle--> ETC

do fatty acids or glucose yield more ATP

fatty acids bc of higher energy CH bonds

how are proteins transformed for energy use?

1. Amine group is removed (NH3) and then discarded bc its toxic

2. the rest of the molecule becomes various molecules like pyruvate, acetyl coA, and glucose--> enters cycle at various stages