Enzymes, Cellular Respiration, Tissues

Question 1

What is an enzyme?

Answer 1

Proteins that allow chemical reactions to take place at normal body temperature.

Question 2

How an does enzyme work?

Answer 2

Energy needed to get a chemical reaction started is down as activation energy. Enzymes decrease the amount needed begin a reaction and allows reactions to occur at a rate to suit the body’s requirements.

Question 3

What is a subtrate?

Answer 3

The molecules on which an enzyme acts. Each enzyme will combine with only one specific subtrate and is therefore involved in only one specific reaction.

Question 4

How a enzyme and subtrate combine?

Answer 4

They combine because they have characteristics that are complementary to one another, the enzyme and substrate have a shape and structure that is complementary to each other to fit together (lock and key). The part in which the enzyme and subtrate fit together is known as the active site when they combine, it is called an enzyme-substrate complex.

Question 5

Describe the different factors affecting enzyme activity

Answer 5

• the higher the concentration of enzyme, the factor the rate of reaction
• increasing subtrate concentration also increases the rate of reaction.
• the products of reaction must be continually removed, otherwise the rate of reaction will slow because it becomes more difficult for the subtrate molecules to make contact with enzyme molecules.
• the rate of most chemical reactions increases as temperature increases
• enzymes are very sensitive to the pHof the medium in which the reaction is taking place.
• many enzymes require the presence of certain ions or non-protein molecules before they will catalyse a reaction (known as co-factors).

Question 6

Define cellular respiration?

Answer 6

A process by which organic molecules, taken in as food, are broken down in the cells to release energy for the cell activities.

Question 7

What is the formula for cellular respiration?

Answer 7

C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy

glucose + oxygen-> carbon dioxide + water + energy

Question 8

Describe what cellular respiration entails.

Answer 8

The breakdown of glucose to carbon dioxide and water involves over 20 reactions which occur in a series.
During each step, an intermediate compound is formed, and each step is catalysed by a different enzyme.
Small amounts of energy is released, making the release of energy controlled rather than happening all at once.
In the process of converting glucose to CO2 + H20, 60% of energy is lost in heat used to maintain body temp, 40& used in ATP

Question 9

Describe ATP and ADP

Answer 9

ATP = Adenosine triphosphate:
Adenosine (strong bond) Phosphate (strong bond) Phosphate (weak bond) Phosphate
The Phosphate at the end has a weak bond, so that it can easily drop off for energy. When it detaches, ATP becomes ADP; adenosine diphosphate.

Question 10

Describe Anaerobic Respiration

Answer 10

• occurs during physical activity
• circ / rest systems needing to increase work to deliver O2 to cells
• occurs without O2
• oxygen debt when physical activity ends

Question 11

Define Glycolysis

Answer 11

The 1st phase of glucose breakdown 10 steps to produce 2 pyruvic acid molecules - break into Lactic Acid

• glycolysis of 1 glucose molecule -> 2 molecules ATP
• occurs in cytosol of cell (liquid of cytoplasm)
• pyruvic acid to lactic acid happens in cytosol
• lactic acid travels to liver to recombine with o2 + stores as glycogen for later use.

Question 12

Describe Aerobic Respiration

Answer 12

• requires O2
• complete breakdown of glucose
• glucose -> CO2 + H2O requires O2
• pyruvic acid breakdown requires O2
• occurs in mitochondria

Question 13

Explain the two stages of Respiration

Answer 13

Stage 1 = produces 2 ATP
Anaerobic = produce 2 pyruvic acid - with no o2 it breaks down into 2 lactic acid, with O2, it enters the mitochondria.
Stage 2= 2 processes (Kreb cycle [produces 2 ATP] and ElectronTransport [34 ATP].

Question 14

What is the potential for glucose to generate 38 ATP

Answer 14

• 2 ATP during anaerobic (cytosol)
• 2 Kreb cycle
• 34 electron transport

Question 15

What are the four types of tissues?

Answer 15

Epithelial
Connective
Muscular
Nervous

Question 16

Describe the functions of epithelial tissue.

Answer 16

It is a covering or lining tissue, protects us from the outside world (skin), absorbs (stomach and intestinal lining), filters (kidney), secretes - forms glands.

Question 17

What are the characteristics of epithelial tissue?

Answer 17

1) Closely attached to each other forming a protective barrier.
2) Always have one free (apical) surface open to outside or inside (cavity) an internal organ.
3) Always has one fixed (basal) section attached to underlying connective tissue.
4) Has no blood vessels but can soak up nutrients from blood vessels in connective tissue underneath.
5) Can have lots of nerves in it (innervated)
6) Very good at regenerating.

Question 18

What are the classifications of epithelial tissue?

Answer 18

1. By shape
   a) squamous - flat and scale like b) cuboidal - as tall as they are wide c) columnar - tall, column shaped.
2. By cell arrangement
   a) simple epithelium - single layer of cells (usually for absorption and filtration)
   b) stratified epithelium - stacked up cell layers (protection from abrasion)

Question 19

What are the functions of connective tissue?

Answer 19

1) Wraps around and cushions and protects organs
2) Stores nutrients
3) Internal support for organs
4) As tendon and ligaments protects joints and attached muscles to bone and each other
5) Runs through organ capsules and in deep layers of skin giving strength

Question 20

What are the three elements of connective tissue?

Answer 20

1) Ground substance - gel around cells and fibres
2) Fibres - provide strength, elasticity and support
3) Cells

Question 21

What are the two kinds of Connective Tissue?

Answer 21

1) Loose Connective Tissue
a) Areolar Connective Tissue - cushion around organs, loose arrangement of cells and fibres.
b) Adipose Tissue - storehouse for nutrients, packed with cells and blood vessels
c) Reticular Connective Tissue - internal supporting framework of some organs, delicate network of fibres and cells.
2) Dense Connective Tissue
a) Dense Regular Connective Tissue - tendons and ligaments, regularly arranged bundles packed with fibres running same way for strength in one direction.
b) Dense Irregular Connective Issue - skin, organ capsules, irregularly arranged bundles packed with fibres for strength in all directions.

Question 22

What are the three types of Special Connective Tissues?

Answer 22

1) Cartilage
2) Bone
3) Blood

Question 23

List the functions of Cartilage as a connective tissue

Answer 23

1) Provides strength with flexibility while resisting wear, i.e. epiglottis, external ear, larynx
2) Cushions and shock absorbs where bones meet, i.e. intervertebral discs, joint capsules.

Question 24

List the functions of Bone as a connective tissue

Answer 24

1) Provides framework and strength for body
2) Allows movement
3) Stores calcium
4) Contains blood-forming cells

Question 25

List the functions of Blood as a connective tissue

Answer 25

1) Transports oxygen, carbon dioxide, and nutrients around the body.
2) Immune response.

Question 26

List the functions of Nervous Tissue

Answer 26

1) Conducts impulses to and from body organs via neurons.

Question 27

What the three elements of nervous tissue?

Answer 27

1) Brain
2) Spinal Cord
3) Nerves

Question 28

What are the functions of Muscle Tissue?

Answer 28

1) Responsible for body movement
2) Moves blood, food, waste through body’s organs.
3) Responsible for mechanical digestion

Question 29

List and explain the 3 types of muscle tissue?

Answer 29

Smooth Muscle - organ walls and blood vessel walls, involuntary, spindle-shaped cells for pushing things through organs.
Skeletal Muscle- large body muscles, voluntary, striated muscle packed in bundles and attached to bones for movement.
Cardiac Muscle - heart wall, involuntary, striated muscle with intercalated discs connecting cells for synchronised contractions during heart beat.