Learning Checks Unit 3

What is first product of carbon fixation, describe experiment used to fix it

expose algae to light, exposure to radioactive CO2 (C14) for short period (3s), algae are drained into ethanol to extract products, produces are run on a filter to seperate based on size(MW) and pI (isoelectric point), when expose filter to film, we see one product after 3 sec, 3PG (3-phosphoglycerate)

What is overall reaction of photosynthesis, identify which are in light reactions and which are in carbon reactions

6CO2+12H2O+energy(light) → 6O2 +6H2O +C6H12O

light in light reaction

Why does the wavelength of light matter for photosynthesis, why only vis spectrum wavelengths

indirectly proportional to energy, so shorter wavelength means high energy, where long wavelength is low energy

• some photons are more useful for photoexcitation of electrons than others

• want to excite E-, not eject, so photons in visible spectrum have intermediate wavelength and intermediate energy (too low energy cant excite, too high ejects it)

3 major products, sequence of events (non-cyclic) ET, and how ATP formed in LIGHT reactions

Makes oxygen, ATP, and NADPH

PSII → q → Cyt B6f → PC → PSI → Fd → FNR → NAHP+

ATP is formed from the proton gradient made by proton pumps

Describe 3 things that are accomplished by oxidation of H2O and why theyre useful

Oxidation of H2O takes electrons and gives them to PSII, replenishing those used in photophosphorylation. Also generates protons, which adds to the proton gradient (useful to make ATP production), and also makes O2, which is used by plants/animals as an electron acceptor in cellular respiration

Compare and contrast non-cyclic electron flow and oxidative phosphorylation

light reaction vs OP: Both use ETC, Proton pumping, and ATP synthesis

non-cyclic: oxidizes water into o2, and last e- acceptor is NADP+, light as energy source

OP: start by oxidizing reduced NADH, last e- acceptor is O2 → reduced to H2O, oxidation energy source

what is precursor molecule/reactant used for fixation of CO2, what is enzyme that catalyzes reaction, what are enzyme limitations

RuBP is is molecule, enyme is rubisco (reacts with O2 so plants need to compenssate by having extra, its inefficients and needs strong conc of CO2, temp-sensitive (rubisco is worse as it warms)

3 phases of CBB cycle, what takes place at each (input/output)

fixation (c02+RuBP→3pg)

reduction (3PG reduced to G3P using ATP and NADPH )

regeneration (5G3P used with ATP to regenerate 3 RuBP)

Summary reaction for CBB cycle

Define photorespiration and why it’s detrimental to the cell

Describe the carbon fixation system in C4 plants and how it differs from C3 plants

Describe the carbon fixation system in CAM plants and how it differs from C3 plants

Define Chromatin, Sister Chromatids, Homologous Chromosomes

What are the three stages of interphase, what happens in each stage

How do cyclin and CDKs (cyclin-dependent kinases) control progression through the cell cycle? Describe the mechanism using CDK4 and cyclin D in G1 as an example

Explain how mutation of each of the tumor suppressors could result in cancer (P21, P53, Ras)

Describe what is taking place during each of the stages of mitosis

Define diploid, haploid, germ line, somatic cell, zygote

If ploidy 2n=2, how many unique chromosomes are present and how many copies of each chromosome

Compare and contrast mitosis and meiosis (parent compared to daughter cell, ploidy at beginning, number of daughter calls and their ploidy)

What takes place during meiosis 1 and meiosis 2 (metaphase and anaphase) and draw it

how does non-disjunction contribute to aneuploidy

how does apoptosis differ from necrosis, why might apoptosis take place, with 3 examples