Energy and enzymes

Question 1

What is energy required for in the body?

Answer 1

for growth, repair, breathing, brain function, reproductive processes,

Question 2

why do cells need energy?

Answer 2

to import materials to the body, make new materials and repair damaged parts

Question 3

what is the importance of carbohydrates within energy?

Answer 3

-consumption of carbs allows sugar to be absorbed and generates energy that can be used by athletes

Question 4

what is energy?

Answer 4

the capacity to work

Question 5

what are the 3 different types of work?

Answer 5

-chemical work
-transport work
-mechanical work

Question 6

what is chemical work and give an example?

Answer 6

-the breaking and making of new chemical bonds
-These allow us to grow and maintain homeostasis and adapt to our environment, store fuels (carbohydrates and fats) needed for future activities
Eg.the joining of amino acids to form proteins and water being removed

Question 7

what is transport work and give an example?

Answer 7

-enables cells to move ions, molecules and large particles through the cell membrane (allows us to transport information around body)
-helps body to maintain homeostasis and helps to create concentration gradient by distribution molecules so concentration is higher on one side of membrane than the other
Eg. calcium concentration in muscle is higher than inside sarcoplasmic reticulum and natural concentration gradient allows calcium to move inside SR and then be released back into muscle driving contraction

Question 8

what is mechanical work?

Answer 8

-used for movement processes
-eg.actin and myosin filaments joining together allowing for muscle contraction and relaxation-sliding filament theory

Question 9

what are the 3 types of energy?

Answer 9

-thermal
-mechanical
-electrical

Question 10

Within energy what 2 different forms can it come in?

Answer 10

-potential and kinetic

Question 11

what is the difference between potential and kinetic energy?

Answer 11

-potential-stored energy when stationary
-kinetic-energy of motion
-Potential energy has to be converted into kinetic energy to become available

Question 12

Describe how energy is stored and transported within biological systems?

Answer 12

-potential energy is stored in concentration gradients and chemical bonds
-is transformed into kinetic energy when needed for chemical, transport or mechanical work
Eg.glucose moving into muscles to be used (kinetic) glycogen is stored in muscles (potential)

Question 13

What is the effect of chemical reactions on energy?

Answer 13

-they transform the potential energy of a chemical bond into kinetic energy for growth
-this is how cells obtain energy from the store of energy in chemical bonds of biomolecules
eg.ATP being converted to ADP by th removal of phosphate and the addition of phosphate and energy
From food to create ATP

Question 14

What is a the potential energy stored in a chemical bond equal to?

Answer 14

potential energy stored in a chemical bond= a molecules free energy

Question 15

what is a chemical reaction?

Answer 15

when one substance is turned into another by the breaking/ making of covalent bonds

Question 16

how are covalent bonds formed?

Answer 16

by the movement of electrons

Question 17

what are the 3 different types of chemical reactions?

Answer 17

-combination reactions (2 reactants into 1 product)
-decomposition reactions (breaking down of 1 product into 2 reactants
-displacement reactions (rearranging of reactants to form products)

Question 18

what is activation energy?

Answer 18

-Activation energy is required for chemical reactions to occur
-is the energy needed to start a reaction (low activation energy means reactions are easier to start, may even be spontaneous)

Question 19

What can reactions be separated into?

Answer 19

-Exergonic and endergonic

Question 20

what are exergonic reactions?

Answer 20

• release of energy due to products having less energy than reactants
  (heat is given off as a result, eg. ATP-phosphate is broken away to produce ADP, additional energy is released therefore allows us to use this energy in movement)

Question 21

what are endergonic reactions?

Answer 21

products have more energy than reactants so energy is taken in (activation energy is trapped in the products)

Question 22

What state can reversible reactions reach and what does the reversibility depend on?

Answer 22

-Reversible reactions reach equilibrium
- -the possibility of it being reversible depends in the net free energy change

Question 23

What are enzymes and what do they do?

Answer 23

-biological catalysts- speed up chemical reactions without being changed by lowering the required activation energy
-are proteins
-substrate + enzyme = products + enzyme

Question 24

how is reaction rate determined?

Answer 24

by speed of disappearance of products or appearance rate of products

Question 25

what are the factors affecting reaction rate?

Answer 25

Heat- speeds up reactions-increases chance of 2 substrates meeting by putting more activation energy in the system
-Concentration of reactants- more of reactants-more likely to collide and react

Question 26

how do enzymes work

Answer 26

-Enzymes bind to substrates at active sites. -They are specific and only bind certain substrates for certain reactions.
-Without enzymes, most metabolic reactions would take much longer and would not be fast enough to sustain life.

Question 27

What 2 factors can impact enzymes?

Answer 27

-Enzymes are sensitive to temperature and pH
-enzymes optimum tmp is 40c (near 37c-core body temp)-above 60c or below freezing enzymes can’t function and can’t carry out chemical reactions (reactions slow down)
-optimum pH around ⅞-neutral

Question 28

what happens to enzymes if they are not in optimum conditions

Answer 28

-they become denatured-active sites are no longer correct shape so cannot bind to substrate

Question 29

What can change the shape of an enzyme?

Answer 29

-they can be activated/deactivated by conformation as an activator/ deactivator binds to the enzyme and changes its shape