metabolic pathway intro and characteristics

Question 1

metabolic pathway

Answer 1

a set of sequential enzymatic reactions to produce the right amount of products… this is why you want enzymes operating at S critical….

Question 2

catabolism

Answer 2

complex to simple

Question 3

anabolism

Answer 3

simple to complex

Question 4

first characteristic. pathway must be overall….

Answer 4

irreversible. because you must have at least one step that has a large negative delta G.

(“1st” [ not always the 1st step] of these is committed step)

Question 5

Why is the cellular form of glucose G6P

Answer 5

• cant remove it from the cell by using gluc transporters.
• they are looking for specific hydroxyl groups, such as those that get phosphorylated by kinases
• if phosphorylated, the glucose transporter moves past it

Question 6

second characteristic… while the entire pathway isnt completely reversible…

Answer 6

turns out many steps are.
only steps 1 3 and 10 are not reversible

Question 7

third characteristic…. How regulated?

Answer 7

enzymatic control, enzymes regulated in many ways as well (allosteric, CI, UI, MI/NI)
- regulated by controlled the committed step enzyme (and other enzymes in the path with a large delta G)

Question 8

fourth characteristic…. if A -> B and B->A are in two separate pathways and non reversible (large -DG)

Answer 8

the enzymes that interconvert them are regulated differently

Question 9

fifth characteristic…. Eukaryotes have…

Answer 9

• specific locations for pathways.
• our focus is on the mito, cyto

Question 10

Many enzymes moonlight?

Answer 10

• meaning many enzymes have more than one job with non metabolic pathway functions