Lecture 3 - 1/5

Question 1

Heterotropic effectors

Answer 1

Where the allosteric regulators bind at sites other than the active site.

Question 2

Homotropic effectors

Answer 2

This causes the S-shape of the allosteric M-M plot

Question 3

feedback inhibition

Answer 3

The last step controlling the beginning step (the committing step)

Question 4

homeostasis

Answer 4

the ability to maintain a steady level of intermediates.

Question 5

Two conformations of concerted model of allosteric regulation

Answer 5

T (tense/taut) state - most stable

R (relaxed) - binds substrate the best

Question 6

Activators stabilize T or R state

Answer 6

R state. Shifts M-M curve to left

Question 7

competitive inhibitors

Answer 7

bind at the active site. they block access to substrate

Question 8

uncompetitive inhibitors

Answer 8

bind to ES complex

Question 9

noncompetitive inhibitors

Answer 9

bind to either E or ES

Question 10

Porphrin rings

Answer 10

have a metal in the middle and 4 pyrrole rings around the outside

Question 11

Cooperative behavior

Answer 11

Similar to homotropic behavior in allosteric enzymes, but in a protein (hemoglobin)

Question 12

Puranose

Answer 12

six-membered ring with an oxygen

Question 13

Furanose

Answer 13

five-membered ring with an oxygen

Question 14

Anomer

Answer 14

up/down configuration (alpha-beta)

Question 15

Glycosyltransferases

Answer 15

add sugar to growing chain (at non-reducing end)

Question 16

Glycosidases

Answer 16

Cleaves sugars

Question 17

linkages of cellulose

Answer 17

beta-1,4 linkages

Question 18

linkages of starch and glycogen

Answer 18

alpha-1,4 and a-1,6 linkages

Question 19

glycoprotein

Answer 19

mostly protein. found in cell membrane

Question 20

proteoglycans

Answer 20

mostly sugar. have aminoacetyl groups, that attract a lot of water. Thus, they are viscous in solution because the water doesn’t flow very well. Found in saliva, lungs.

Question 21

N-linked glycoproteins

Answer 21

formed by the condensation reaction with asparagine, connected by N. The chain of mannose sugars gets assembled ahead of time and the linked to asparagine en masse. N-liked polysaccharides are high-mannose.

Question 22

O-linked glycoproteins

Answer 22

formed by the reaction with the O on the side-chain from serine or threonine. The sugars are added to the glycoprotein one at a time.

Question 23

Job of proteoglycans

Answer 23

Take up volume in extra-cellular space to provide a cushion. Cartilage is mostly extra-cellular matrix

Question 24

Zymogen

Answer 24

An enzyme in its inactivated state. It can be modified by other enzymes or a change in its environment to take on the activated state.

Question 25

Mucin

Answer 25

Are often lubricants because of their high percentage of aminosugars, which makes them viscous. Similar to proteoglycans.