Bio 112 - cycles of stuff

Steps of aerobic respiration

• Where

• inputs and outputs

1. Glycosis: inputs: glucose, 2 ATP; produces 2 pyruvate, 2 NADH, 4ATP (net ATP gain = 2)

2. Pyruvate processing: input = 2 pyruvate; output = 2 Acytl CoA

3. Citric Acid cycle: input = 2 acytl CoA, 6 NAD, 2 FADH, 2ADP; output = 6NADH, 2FAD, 2 CO2, 2ATP

Electron transport chain (aerobic respiration)- inputs and outputs

C1: inputs = NADH; output = NAD

• H+ across membrane; move electrons to Q

C2: Inputs = FAD; output = FADH

• move electrons to Q

C3: Inputs: electrons from Q; Outputs: H+ across membrane

• electrons to C

C4: Inputs: Electrons from C, O2; output = H2O

• H+ across membrane

ATP Synthase - inputs and outputs

Input = H+ (brings it back inside membrane), XADP + P; Output = XATP

NAD vs NADP

NAD = catabolic pathways (in animals) - Excess accelerates oxidation of sugars (and generation of NADH

NADP = anabolic pathways (in plants) - Excess drives biosynthetic reductions

Explain the antennas (light harvesting complex)

Increase surface area = increase in probability light energy captured

Excitation travels from one molecule to the next by resonance energy transfer, ultimatly ending up in the middle where excited state is the lowest amount of energy (680nm in 1st, 700nm in 2nd)

Electron Transport chain Z Scheme (photosynthesis)

2 systems required bc 1 quantum of light is not strong enough to transfer electrons from H2O to NADP and make ATP

Part 1: Antenna (min 680) receives 2 H20 & 4 Photons; breaks H2O into 4H+ and O2 → electrons travel to electron transport chain:

• pheophytin → photosystem 2→ PQ (carrier) → cytochrome complex → ATP Synthase produces ATP

Part 2: antenna (min 700) receives 4 photons + H2O; Break up H20, electrons go to electron transport chain:

• Ferredoxin → Photosystem 1 → [2 NADP + 2H+ = 2NADPH]

Electron Transport Chain Cyclic (photosynthesis)

photosystem 1 [photons + H20] = electron → transport chain [Ferredoxin → PQ → Cytochrome complex] → PC → photosystem 1

• electron transport chain makes ATP

Calvin Cycle

1) Fixation of Carbon dioxide [ RuBP + 3CO2 = 6x 3-phosphoglycerate]

2) Reduction of 3-phosphoglycerate [6 ATP + 6NADPH + 6x 3-phosphoglycerate = 6 (ADP + P, NADP + H) + 6G3P

• 1G3P → gluctose/fuctose

3) Regeneration of RuBP [5 G3P + 3 ATP = RuBP + 3(ADP + P)]

The Cell Cycle

G1 = Rest

S phase = DNA duplication (end up with 2 copies of each chromosome)

G2 = prep for division → wrapping of DNA around histones

M Phase = Mitosis (for exact clones) OR Meiosis (to mix genetic material)

*Cytokinesis (optional) = dividing the cytoplasm in two

How many chromosomes do humans have - how many homologs?

46 Chromosomes → 23 Homologs (“identical” chromosome pairs - after replication there are 2 sister chromatid sets in 1 homolog)

Steps of Mitosis

1. Prophase = Nuclear envelope dissolves, centrosomes move to poles → create spindle → MT’s probe for kinetochores (on the connecter of sister chromatids)

2. Metaphase = when kinetochore MT from each pole connects to sister chromatids, its pulled to central line - all sister chromatids must be in center line to continue

3. Anaphase = MT’s pull apart sisters - one to each pole

4. Telophase = reforming of nuclear envelope, chromosomes decondense

Haploid vs diploid (gametes vs somatic cells)

Gametes (sperm/egg cells) only have one homolog (1n) of each chromosome (one set of sister chromatids post-replication) → gametes are haploid

Somatic cells have 2 homologs (2n) of each chromosome (2 sets of sister chromatids post-replication) → somatic cells are diploid

Steps of Meiosis

Start with Diploid Cell (2 sets of sister chromatids post-replication)

1. Prophase 1 = Nuclear envelope dissolves, centrosomes move to poles → create spindle → MT’s probe for kinetochores (on the connecter of sister chromatid PAIRS) ALSO, crossing over of genetic info occurs (synapsis)

2. Metaphase 1 = sister chromatid pairs, once connected to both poles by MTs, pulled towards center

3. Anaphase - Sister chromatid pairs pulled apart - one set of sister chromatids to each pole

4. telophase 1 = optional

5-9 (meiosis 2) = same as Mitosis but with ½ the sister chromatids

Test Cross vs Dihybrid Cross

Test cross = cross plant 1 (dom phenotype, unknown genotype) with plant 2 (recessive phenotype → known genotype) to figure out genotype of plant 1

Dihybrid cross = test if phenotypes are attached or independent (if attached, result would be same phenotype ratios of parents)

Traits unlinked vs linked in trans vs linked in cis

• Cross BbVv x bbvv

Unlinked: ¼ of each: bbvv, bbVv, Bbvv, BbVv

Linked in trans (opposite chromosome): ½ bbVv & ½ Bbvv

Linked in cis (same chromosome) : ½ Bbvv & ½ BbVv

Recombination Rate → measured in what?

Recombination rate = measure of distance → More recombination = further apart genes

Measured in cM (100*# recombinants/# total progeny)