Turn Class Notes Into Exam Prep

Unit 4 Cellular Respiration. Glycolysis occurs in the cytosol. One glucose molecule is split into two pyruvate molecules. The net yield is ATP and NADH. Glycolysis does not directly require oxygen, but the later electron transport chain depends on oxygen as the final electron acceptor.

Pyruvate oxidation connects glycolysis to the citric acid cycle. Pyruvate moves into the mitochondrion and is converted into acetyl-CoA. Carbon dioxide is released, and NAD+ is reduced to NADH.

Citric acid cycle occurs in the mitochondrial matrix. Each acetyl-CoA enters the cycle and contributes to the production of carbon dioxide, NADH, FADH2, and ATP or GTP. Most ATP is not produced directly in this cycle; most ATP comes from oxidative phosphorylation.

Electron transport chain occurs on the inner mitochondrial membrane. NADH and FADH2 deliver high-energy electrons to protein complexes. Protons are pumped into the intermembrane space, creating a gradient that ATP synthase uses to make ATP.

Oxygen receives electrons and protons at the end of the electron transport chain to form water. If oxygen is unavailable, electron flow slows, NADH cannot be efficiently oxidized back to NAD+, and ATP production through oxidative phosphorylation drops.

Photosynthesis light reactions occur in the thylakoid membrane. Inputs include light energy and water. Outputs include ATP, NADPH, and oxygen. Oxygen comes from splitting water during the light reactions.

Calvin cycle occurs in the stroma. It uses carbon dioxide, ATP, and NADPH to build sugar precursors. The cycle depends on products from the light reactions but does not directly require light in the same way as the thylakoid reactions.

Genetics review. For a monohybrid cross, identify each parent genotype, list possible gametes, set up the Punnett square, and then calculate genotype and phenotype ratios. Homozygous dominant, heterozygous, and homozygous recessive genotypes must be distinguished before writing ratios.

Dihybrid cross section. For AaBb x AaBb, assume independent assortment only when the problem does not indicate linkage. Each parent can produce AB, Ab, aB, and ab gametes. The 16-square grid represents all combinations of these gametes.

Linkage paragraph. Genes close together on the same chromosome do not assort independently as often as genes on different chromosomes. Recombination frequency can be used as a rough indicator of distance between linked genes.

Population ecology section. Exponential growth produces a J-shaped curve when resources are not limiting. Logistic growth produces an S-shaped curve as population size approaches carrying capacity.

Carrying capacity section. Limiting factors include food availability, space, predation, disease, waste buildup, and environmental change. A population curve that levels off should be connected to resource limits rather than treated only as a vocabulary label.

Predator-prey graph section. Prey population often changes before predator population because predator reproduction and survival depend on available prey. Lag between curves is expected in many simplified predator-prey models.

Lab graph interpretation page. Read the x-axis, y-axis, units, time scale, control group, and treatment group before interpreting a result. A graph answer must match the measured variable, not just the topic name of the lab.