Biological Molecules And Enzymes

Question 1

Competitive inhibitors

Answer 1

Binds to enzyme (active site)
Inhibits binding of substrate 
Increases Km
No change on Vmax
On graph, the lines of competitors cross like swords.

Question 2

Uncompetitive inhibitors

Answer 2

Bind to enzyme-substrate complex
Decreases Km
Decreases Vmax

Question 3

Mixed inhibitors

Answer 3

Bind to either enzyme or enzyme- substrate complex
Increases or decreases Km depending on whether they bind to enzyme or E-S complex
Decreases Vmax

Question 4

Non competitive inhibitors

Answer 4

No preference between binding enzyme or E-S complex
No change to Km
Decreases Vmax
On graph, lines meet at x-intercept (1/Km)

Question 5

Oxidoreductases

Answer 5

Catalyze the transfer of electrons or hydrogen ions i.e. Oxidation-reduction reactions

Question 6

Transferases

Answer 6

Catalyze reactions in which groups are transferred from one location to another

Question 7

Hydrolases

Answer 7

Regulate hydrolysis reactions

Question 8

Lyases

Answer 8

Catalyze reactions in which functional groups are added to double bonds or double bonds formed via the removal of functional groups.

Question 9

Isomerases

Answer 9

Catalyze the transfer of groups within a molecule with the effect of producing isomers

Question 10

Ligases

Answer 10

Catalyze condensation reactions coupled with the hydrolysis of high energy molecules

Question 11

Negative feedback

Answer 11

One of the products downstream in a reaction series comes back and inhibits the enzymatic activity of an earlier reaction.

Question 12

Lipids

Answer 12

nonpolar and hydrophobic
roles: energy storage, cellular organization and structure, provision of precursor molecules for vitamins and hormones.
major groups: fatty acids, triacylglycerols, phospholipids, glycolipids, steroids, terpenes and waxes.

Question 13

fatty acids

Answer 13

long chains of carbons truncated at one end by a carboxylic acid. usually contain even number of Cs.
Saturated - only single bonds
Unsaturated - one or more double bonds
store more energy per gram than any other macromolecule.

Question 14

triacylglycerols or triglycerides

Answer 14

three carbon backbone (glycerol) attached to three fatty acid chains.
function: store energy and provide thermal insulation and padding to an organism.

Question 15

phospholipids

Answer 15

lipids with a phosphate group attached.
phosphoglycerides: glycerol backbone but a polar phosphate group and two fatty acid chains.
amphipathic
major component of biological membranes.

Question 16

steroids

Answer 16

four ringed structures

include hormones, vitamin D and cholesterol

Question 17

waxes

Answer 17

formed by an ester linkage between a long-chain alcohol and a long-chain fatty acid.