Chapter 7: How Cells Harvest Energy

MATES Biotechnology, Sprague 2024

heterotrophs

organisms that consume other organisms for energy

autotrophs

organisms that can create their own energy

what is aerobic respiration?

• respiration that involves oxygen as the final electron acceptor (aerobic ~ air/oxygen)

• occurs in the mitochondria

what is produced at the end of glycolysis?

2 pyruvate, 2 ATP, 2 NADH, 2 H2O

what is decarboxylation?

• removal of a carbon atom as carbon dioxide

• ex: when pyruvate cleaves one carbon atom—it leaves as CO2

  • pyruvate → acetyl-CoA

where does glycolysis take place?

cytoplasm

where does aerobic respiration take place?

in the mitochondria

what causes lactic acid fermentation?

in the absence or lack of oxygen, muscle cells regenerate NAD+ by converting pyruvate into lactic acid

role of NAD+ and NADH

• NAD+ accepts electrons, electron carrier

• NADH stores high energy electrons to donate to the ETC

evolutionary stages of cell respiration

glycolysis, anaerobic respiration, aerobic respiration; evolved in response to rising environmental oxygen levels

chemiosmotic generation of ATP

as electrons move through the ETC they pump protons into the intermembrane space creating a high concentration of protons. as the protons flow back into into the matrix through ATP synthase, it provides. the energy needed to convert ADP to ATP