Human Physiology Ch 4

Helpfulness: 0
Set Details Share
created 6 years ago by hoovemaa
13 views
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:
1

chemical reactions

break in chemical bonds in reactant molecules

makng of new chem bonds to form product molecules

energy is added or released

2

reversible chemical reactions

A+B <-> C+D+ small amount of energy

3

irreversible chemical reactions

E+F -> G+H + large amount of energy

4

increase in substrate =

increase in products, this drives the reaction in the opposite direction

5

reaction rates are determined by what?

reactant concentration

temperature

presence of catalysts

6

what are enzymes?

protein catalysts

7

catalysts

speed up rate of chemical reaction by lowering the activation energy

are not changed by reaction

do not change the nature of the reaction

catalyze reactions by binding the reactants substrates by orienting themselves so that less energy is needed to start the reaction

8

activation energy

energy required for the reactants to engage and react with one another

9

lock and key model

active site specificity

bind to specific substrates

catalyze specific chemical reactions

produce specific products

force substrates to line up and interact in a specific way

10

control of enzyme mediated reactions

pH

substrate concentration

enzyme concentration

enzyme activity

these will drive the reaction in one direction

11

effects of pH

enzymes exhibit peak activity within a narrow pH range

pH changes alter the shape of protein affecting catalytic ability, this is called denaturation and it changes the activation site

12

as substrate concentration increase so does the rate of reaction, why?

up to the point of saturation, limited by the number of enzymes

13

enzymatic affinity

how well an enzyme binds to the substrate

dependent on the shape of the activation site

"how well the key fits"

14

coenzymes

are smaller and needed to aid in a reaction

derived from water soluble vitamins (B, C)

transport hydrogen atoms and other molecules between enzymes

15

cofactors

help form the active site through conformational change of the enzyme or help in enzyme substrate binding

are metal ions such as Ca2+ Mg2+ Mn2+ Cu2+ Zn2+

16

end product inhibition

inhibition of rate-limiting enzyme by final product

is a negative feedback

keeps the final product from accumulating

17

bioenergetics

flow of energy in living systems

18

first law of thermodynamics

energy cannot be created or destroyed only transformed

energy is often lost as heat

change of energy is not 100% efficient

19

endergonic reactions

chemical reactions that require input of energy

ie plants need energy from light to turn CO2 and water into glucose

20

exergonic reactions

chemical reactions that produce energy

ie breaking down glucose into CO2 and water produces energy

many times coupled together

21

ATP

adenosine triphosphate

production is an endergonic driven by an exergonic reactions

molecule stores energy in its bonds to be used elsewhere

22

energy from glucose

is broken down slowly in order to allow for slower release of energy

if it was broken down to quickly energy would be release too quickly for body to use

23

calorie

how the amount of energy in a molecule is measured

1 calorie = the amount of heat needed to raise 1 gram of water by 1 degree Celsius