extra Flashcards
Where do the light reactions take place?
Thylakoid membrane of chloroplast
What enzyme catalyzes the fixation of carbon dioxide to an organic molecule?
Rubisco
What are the outputs of the light reaction in photosynthesis?
ATP
NADPH
Oxygen
Photorespiration occurs when…
Rubisco fixes oxygen on the 5-carbon sugar instead of carbon dioxide
How does the modification in C4 plants minimize photorespiration?
Increases carbon dioxide concentration and minimizes oxygen concentration at the point where Rubisco is operating
What is the immediate source of electrons entering the ATP-generating electron transport chain in photosynthesis?
Excited P680
Excited P700
NADPH
Excited P680
What is the immediate output of the Calvin cycle?
Glyceraldehyde-3-phosphate
what produces Co2
CAC, pyruvate oxidation
What are benefits of lactic acid fermentation to an animal cell where aerobic respiration is unavailable?
-Prevents build-up of toxic pyruvate molecules
-Refreshes NADH to NAD+ so glycolysis can continue
What is the function of telomeres?
Buffer the chromosomes against the effects of shortening with each round of replication
Why does anaerobic respiration not generate as much ATP as aerobic respiration?
-The electron acceptor in anaerobic respiration takes electrons before they travel all the way down the electron transport chain and give up all their energy
-Anaerobic respiration does not fully oxidize glucose
Why can translation in prokaryotes start while RNA polymerase is still transcribing a gene?
-Prokaryotic genes do not have introns
-Ribosomes and DNA are not in isolated compartments within prokaryotic cells
Which part of the final, mature RNA molecule was present in the initial RNA transcript, as synthesized by the RNA polymerase?
Exons
The genetic code is unambiguous and redundant. What does this mean?
Each codon codes for one amino acid, but an amino acid may be coded for by several different codons
During translation and protein synthesis, the peptide bond joining the new amino acid to the growing protein is created when…
The protein is detached from the tRNA in the P site and attached to the amino acid on the tRNA in the A site