AP Bio U3 Test: Chapter 7 + 4.5 Concept

Mitochondrial Semi-Independance

semi-independant (grow, reproduce, DNA, ribosomes)

Mitochondrial Structure: 4 Main Areas

outermembrane, intermembraine space, cistae, inner membrane, mitochondrial matrix

Endosymbiont Theory

chloroplasts and mitochondrai envolved on their on and were engulfed

Evidence for endosymbiosis

double membrane
outer —> engulfed membrane
inner —> resembles bacterial membrane

circular DNA
division by binary fission

Serial Endosymbiosis

mitochondria came first (all eurkaryotes had or have them), chloroplass came later only in the algae and plant lineage

OIL RIG

Oxidation in loss, reduction is gain

Cellular Respiration Formula

C6 H12 6O2 —> 6CO2 + Energy (Atp + Heat)

Free energy released in cellular respiration

-686 kcal/mole

How is stability related how the distance electrons are from the nucleus?

electrons shared between carbon and hydrogen are both far away from the nuclei because they have low electronegavity. Because they are loosely held and far apart they have potential energy + unstable

Electron's route:

food —> NADH —> ETC —> O2

Why is energy released in cellular respiration?

1. electrons in C-H bonds are high energy electrons (because they are unstable)

2. electrons toward oxygen during reactions, stable-low energy state

3. chemical energy is released as electrons transition to lower energy state

4. ATP captures potential energy release to build ATP

substrate level phosphorylation

an ezyme moves a phosphate form a substrate straight onto ADP —> makes a bit of ATP in glycolysis and the Kreb's cycle

oxidative phosphorylation

ATP made using the H+ gradient that the ETC builds, makes 90% of the ATP (26-28)

draw all the models for cellular respiration detailing inputs, outputs and location (list order + here)

Glycolysis —> Link Reaction (pyruvate decarboxylation) —> Kreb's Cycle —> Oxidative Phosphorylation

Glycolysis Definition

10-step anerobic metabolic pathway that splits one molecule of a 6-carbon glucose into two molecules of 3-carbon pyruvate

Glycolysis: Two major phases

Energy Investment (1-5), Energy Payoff Phase (6-10)

Glycolysis: Energy Investment (spends 2 atp)

Step 1: hexokinase adds phosphate to glucose (phosphorylation) (spends 1 atp)
Step 2: another intermediate (F6P)
Step 3: phosphofructokinase (spends 1 atp / adds second phospate)
Step 4: adolase splits the 6-sugar into G3P & DHAP
Step 5: Isomerase converts DHAP into G3P (no equillibirum)

What does ATP inhbit in the energy investment phase and why?

inhibits enzyme PFK, when there is too much ATP it spills over and allosterically inhibits PFK too stop it from over using ATP to phosphorlyate glucose intermediates

what is substrate level phosphorylation? (in context of glycolysis)

directly transfers a high-energy phosphate group from an intermediate substrate molecule to ADP, forming ATP without needing an electron transport chain or oxygen

Glycolysis: Energy Payoff (happens 2x for each glucose, once for each G3P)

Step 6: Oxidize G3P attach inorganice phosphate (produce 2 NADH)
Step 7: Generate 4 ATP via substrate level phosphorlation
Step 8&9: rearrange into PEP and enolase release 2H2O
Step 10: Pruvate kinase converts PEP to 2 Pyruvate via SLP

Net Output of Glycolysis

2 ATP (4ATP - 2ATP) + 2 NADH + 2 pyruvate + 2H2O

Pyruvate Oxidation / Link Reaction def

converts pyruvates into acetyl-CoA

Pyruvate Oxidation: First Step + Details

Decarboxylation: Carboxyl group leaves as CO2 (first Co2 release)

Pyruvate Oxidation: Second Step + Details

Oxidation: the 2 carbon grament is oxidized (NAD —> NADH) now called an acetyl group

Pyruvate Oxidation: Third Step + Details

Coenzyme A attaches: making the reactive acetyl CoA

Pyruvate Oxidation: Outputs per Glucose

no ATP, 2 Co2, 2 NADH, 2 acetyle CoA

Kreb Cycle def

breaks down pyruvate into usable energy in the form of ATP

Kreb Cycle Input + Outputs Tracker: (draw this out)

Acetyl CoA (2) —> CoA Leaves —> Citrate (2 + 4 from oxaloacetate) —> Co2 lost as NAD-NADH (goes to ETC) —> 5 carbon intermediate —> Co2 lost as NAD-NADH (goes to ETC) —> 4 carbon intermediate —> ATP-ADP (via SLP) —> FAD-FADH (goes to ETC) —> NAD+-NADH (goes to ETC) —> oxaloacetate (4)

Kreb Cycle Outputs for one cycle (2x for one glucose)

2Co2, 1 ATP, 1 FADH, 3 NADH

cytochrome def

electron carriers found in mitochondria

units that include electron transport chain

talking about the tranportation of eletrons from complex 1,2,3,4 via CoQ and CycC

units that include chemiosmosis

ATP synthase

which complex does NADH oxidize too? What does complex do? Where do the electrons go to after?

oxidizes to complex 1, complex one pump H+ into intermembrane space , go to CoQ

which complex does DADH oxidize too? What does complex 1 do? Where do the electrons go to after?

oxidzez to complex 2, complex 2 passes electrons to CoQ (does not pump)

What does CoQ do with the electrons, what does the compex do?

transferred both electrons from 1&2 to complex 3, complex 3 pumps H+ into intermembrane space

What does complex 3 do with the electrons? What does that complex do?

complex 3 transfers to complex 4, complex 4 pumps H+ into intermembrane space and passes electrons to electronegative oxygen acceptor

What does oxygen do?

O2 is the final electron acceptor and turns into 2H2O with 4 electrons and 4H+ ions

Does ETC make ATP?

No, the ETC makes no ATP directly, it uses the energy of the electrons to actively pump H+ from matric to intermembrane space

What does all this H+ pumping create?

electrochemical gradient or proton-motive force

what is the proton motive force?

the H+ gradient

Chemiosmosis & ATP Synthase: steps describing facilitated diffusion and ATP synthase

H+ flows down into matrix via facilitated diffusion through ATP synthase, flow spins rotos, and turning rod activates the catalytic knob which makes ADP to ATP

What if scenarios: No O2

electrons backed up without having final electron acceptor and electron carriers cannot be oxidized so kreb cycle stops, glycolysis and fermentation continue

What if scenarios: Uncoupler (membrane leaky to H+ used by brown fat to make heat for babies)

electrochemical gradient collapses, atp synthesis decreases, ATC runs faster trying to rebuild gradient so O2 consumption increases, energy becomes heat

What if scenarios: ATP Synthase Blocked

H+ gradient builds up to much, ETC slows, O2 usage drops

ETC complex blocked

no ATP from oxidative phosphorlyation

Pathway of pyruvate after glycolysis depending on oxygen availability

oxygen present: pyruvates goes through oxidation into mitochondrial matrix
oxygen not present: pyruvate stays in cytoplasm and fermentation convets pyruvate to lactate/(ethanol + Co2 in yeast and plants)

pyruvate is the ____ in the ____

pyruvate is the fork in the road dependant on oxygen availability

Purpose of fermentation

regenerate NAD+ so glycolysis can keep making 2ATP (fermentation makes no ATP)

Steps of alcohol fermentation

glucose → 2 pyruvates via glycolysis (2 ATP + 2 NADH)→ remove CO2 to form acetaldehyde (2) and final electron acceptor for NADH —> reduced into ethanol

who uses alcohol fermentation

yeast and some bacteria

steps of lactic acid fermentation

glucose → 2 pyruvates via glycolysis (2 ATP + 2 NADH)→ pyruvate acts as the electron acceptor —> pyruvate reduved by NADH → lactate

how much Co2 is released in lactic acid fermentation

none

does fermentation use ETC?

no

what is the purpose of fermentation again?

regenerate NAD+ so glycolysis can keep making 2ATP (fermentation makes no ATP)

similarity and difference of aerobic respiration and anerobic respiration

both use glyolysis and NAD+ as oxidizing agent, aerobic makes 32ATP while fermentation makes 2ATP

facultative anaerobes

switch between aerobic and anaerobic pathways

why do facultative anaerobes use sugar faster?

fermation is less efficient and cell must comsume more sugar to produce same amount of ATP to survive

Obligate anerobes

cannot survive with oxygen around

make a table for glycolysis, pyruvate oxidation, krebs cycle and oxidative phosphorlation, and fermentation types with the location, inputs, outputs and # of ATP

ok