body systems part 2 quiz 1

Question 1

What are reactions in living organisms regulated by?

Answer 1

ptotein catalysts called enzymes

Question 2

What do enzymes control?

Answer 2

cells chemical reactions (metabolism)
-control speed of reaction

Question 3

What are catalysts?

Answer 3

enzymes that regulate the speed of a reaction without being themselves altered

Question 4

Why are not many catalysts required?

Answer 4

because they can be used over and over again

Question 5

What do catalysts do in relation to activation energy?

Answer 5

lowers it without adding heat

Question 6

what is activation energy?

Answer 6

amount of energy required to start a reaction

Question 7

what can enzymes be used for?

Answer 7

breaking down substances (catabolism) or build substances (anabolism)

Question 8

What is a substrate?

Answer 8

the molecule on which enzyme works

Question 9

what is the active site?

Answer 9

the area where the substrate and enzyme join

Question 10

what do some enzymes require the help from?

Answer 10

coenzymes (vitamins) and cofactors (minerals) to help them bind to substrates

Question 11

What affects enzyme reaction?

Answer 11

1. temperature due to each enzyme workung best at specific temperatures
2. PH, each enzyme works best at specific PH

Question 12

What happens to enzymes in changes of temperature?

Answer 12

they denature or coagulate

Question 13

What happens to the concentration of substrate when there are no enzymes?

Answer 13

faster reaction

Question 14

What happens to the concentration of substrate when there are enzymes?

Answer 14

faster reaction but at a certian point the rate levels fall off due to the limit in the speed of the enzyme can work

Question 15

What are competitive inhibitors?

Answer 15

molecules that have similar shapes to substrate so they compete with the substarye for active sites on the enzymes
ex, carbon monoxide, cyanide

Question 16

What are 2 inhibitors?

Answer 16

1.Malathion
2.Pencillin

Question 17

What is malathion?

Answer 17

insecticide inverersibly binds to important nervous system enzyme

Question 18

What is penicillin?

Answer 18

bacteria need to make cell walls, no cell walls means they cant reproduce

Question 19

what is precursor activity?

Answer 19

-The activation of the last enzyme in a metabolic pathway by the initial substrate combining with the regulatory site.
-This initial meeting creates a better fit for the molecules, speeding up production of final products. “On Switch”

Question 20

what is feeback inhibition?

Answer 20

-The final product in an enzyme pathway turns off the whole pathway.
– Regulates amount of product, too much of anything isn’t good.
-“Off Switch”

Question 21

what are both feedback and precursor activity termed?

Answer 21

allosteric activity

Question 22

what is allosteric activity?

Answer 22

change in enzyme shape causd by the binding of a molecule

Question 23

what is the benedict reagent test?

Answer 23

determines concentration of reducing sugars.
-when added to colourless solution, after heating solution goes from blue to green/yellow ( trace amounts), orange/red (moderate amounts), dark red (a lot)

Question 24

what is the iodine test?

Answer 24

detetcs presence of starch
-iodine solution turns blue/purple when starch is present

Question 25

what is the Biuret test?

Answer 25

presence of proteins
-solution turns violet/purpe when protein is present

Question 26

what is the sudan IV dye test?

Answer 26

presence of lipids
-forms an orange colour (does not dissolve, top layer will show)

Question 27

what is the brown paper test?

Answer 27

presence of fats
-when a substance with lipids is placed on the brown bag, bag turns translucent.