What does heterotroph and autotroph mean?

[ct:)]

What does heterotroph and autotroph mean?

[anonymous1]

autotrophs can synthesize their own organic compounds, for example plants and some bacteria (cyanobacteria), whereas heterotrophs must obtain organic compounds via nutrients

[ct:)]

thanks, but where does the nutrient come from for heterotrophs?

[anonymous1]

they eat animals which eat plants or they can directly eat plants, plants make organic compounds

[ct:)]

ohh, thankyou

another question is:

Cats that have not been fed for 2-3 days are able to maintain a constant blood glucose concentration. After 24 hours without food, the structure from which glucose is realeased into the cat's blood is the:

a) liver
b) brain
c) pancreas
d) digestive system

I said c) pancreas, but the answer is actually a) liver , why is it in the liver not pancreas?

[jasoN-]

After 24 hours without food, the BG levels are low.
This stimulates glucagon release from alpha cells of the pancreas (what probably confused you), which stimulates liver and kidney cells (mainly liver though!) to release glucose from stored glycogen into the blood.

edit: oops, didn't see cats are able to maintain constant BGL... well regardless, it's the liver releasing glucose (from glycogen) into the blood

Also the pancreas doesn't release glucose. It only releases glucagon and insulin, which stimulate the uptake/release of glucose.

[ct:)]

so glucagon is released by the pancreas which then converts to glucose when needed? and insulin produced by the pancreas converts glucose into glycogen as energy storage in the liver? is that right? :S haha

[jasoN-]

Glucagon stimulates release of glucose (from glycogen - which is the storage form of glucose, i.e. lots of glucose joined together = glycogen)
Insulin stimulates uptake of glucose into cells, where it's used as an energy source, or stored as glycogen

[ct:)]

When does clonal expansion happen?

[scar]

Clonal Expansion is when a particular B cell is activated (the one who can make an antibody that fits with a specific antigen) it clones itself and forms plasma cells and memory cells!

[ct:)]

does kreb cycle occur in the matrix, the inner compartment of mitochondria? and does electron transport occur in the cristae, the inner membrane of mitochondria?

what is the difference between cytochrome and cristae?