Human metabolic processes and energy use. Plant metabolism belongs in Plant Physiology.
Test your knowledge with these top questions!
During an intense sprint, human muscle converts pyruvate into which compound?
Converting pyruvate to lactate lets glycolysis keep running fast when muscles cannot get enough oxygen.
Which hormone signals the liver to break down glycogen into glucose?
Insulin promotes glycogen storage after eating, while glucagon triggers its release when sugar runs low.
Where in a human cell does glycolysis take place?
Glycolysis runs in the watery cytoplasm, so it can make quick energy without using the mitochondria or oxygen.
Which structure in human cells produces most energy from food?
Hardworking muscle cells hold thousands of mitochondria because movement burns so much energy.
Liver glycogen mainly helps humans do what between meals?
Liver cells release glucose into the blood, keeping the brain fueled between meals and overnight.
Which hormone signals human cells to take up glucose for glycolysis after a meal?
Released after eating, insulin moves glucose transporters to cell surfaces so tissues absorb sugar from the blood.
Besides carbon dioxide, which substance forms during human cellular respiration?
Cells join oxygen with hydrogen from food to make this water, which then joins body fluids.
During prolonged fasting, ketone bodies mainly fuel which organ?
The brain cannot burn fatty acids directly, so ketones supply much of its energy during starvation.
Which organ produces ketone bodies during fasting or low-carb diets?
The liver converts fatty acids into ketones that other organs can burn when glucose runs low.
Glycogen consists of stored chains of which sugar?
Glycogen is a branched chain of glucose that the body breaks apart when quick energy is needed.