Module One

Question 1

What is a prokaryotic cell?

Answer 1

Organisms made up of a single cell. They do not have a nucleus or membrane bound organelles.

Question 2

What is a eukaryotic cell?

Answer 2

A cell or organisms that possesses a clearly defined nucleus. They have numerous membrane bound organelles and DNA.

Question 3

What do all cells have?

Answer 3

A cell membrane, cytoplasm, DNA and ribosome.

Question 4

What is the field of view in mm for each magnification?

Answer 4

40x = 5mm
100x = 2mm
400x = 0.45

Question 5

Define cell membrane.

Answer 5

the cell membrane surrounds the contents of the cell and separates it from its external environment. It is selectively permeable which means it allows only certain molecules or ions into or out of the cell.

Question 6

Outline the fluid mosaic model.

Answer 6

The FMM represents our current understanding of the structure of the cell membrane. It suggests that the membrane is composed of a bi-layer of phospholipids.

Question 7

What are the three types of membrane proteins?

Answer 7

• Transport proteins: allows specific substances to move across.
• Receptor proteins: communicate with other cells.
• Recognition proteins: aka antigens that distinguish between foreign particles and the body’s own cells.

Question 8

What does the permeability of cell membrane depend on?

Answer 8

the molecules:
- size
- electrical charge
- Lipid solubility

Question 9

What is diffusion?

Answer 9

Diffusions is the movement of molecules from an area of high concentration to an area of low concentration until an equilibrium has been reached. It is passive.

Question 10

What is facilitated diffusion?

Answer 10

The passive movement of a molecule that is too large to pass through the membrane directly, so it moves through a channel or carrier protein.

Question 11

What is osmosis?

Answer 11

The net movement of water molecules from a region of high concentration to a region of low concentration

Question 12

What is a hypotonic solution?

Answer 12

If the extracellular fluid has lower osmolarity than the fluid inside the cell.

Question 13

What is a hypertonic solution?

Answer 13

if the extracellular fluid has a higher osmolarity then the cell’s cytoplasm.

Question 14

What is active transport?

Answer 14

The movement of materials across a membrane against their concentration gradient, via a specific carrier protein.

Question 15

What is bulk transport?

Answer 15

involves the movement of materials, too large to pass through a carrier or channel, in membrane-bound vesicles that fuse with the cell membrane. Endocytosis and Exocytosis.

Question 16

What is endocytosis?

Answer 16

A type of active transport that moves particles into a cell. The cell membrane changes shape, surrounds the particle and engulfs it.
- Phagocytosis: when the material being engulfed in endocytosis is a solid.
- Pinocytosis: when the material being engulfed in endocytosis is a liquid.

Question 17

What is exocytosis?

Answer 17

A process by which the contents of a cell vacuole are released to the exterior by the fusion of the vacuole membrane with the cell membrane.

Question 18

What are the four factors affecting the exchange of materials across membranes?

Answer 18

• Chemical factors: eg. dissolving in the phospholipid bilayer.
• Physical factors: size and shape.
• Concentration gradient: higher gradient quicker diffusion.
• SA:V ratio.

Question 19

What is an organic compound?

Answer 19

A compound that contains carbon bonded to hydrogen.

Question 20

What is the chemical equation for photosynthesis?

Answer 20

6CO2 (g) + 6H2O (l) → C6H12O6 (aq) + 6O2 (g)

Question 21

What is the chemical equation for cellular respiration?

Answer 21

C6H12O6 (aq) + 6O2 (g) → 6CO2 (g) + 6H2O (l)

Question 22

What is an enzyme?

Answer 22

A protein molecules that controls all metabolic reactions in living cells. They act as a biological catalyst, controlling the rate of reaction.

Question 23

What is the purpose of an active site?

Answer 23

It is where reactants, also known as substrates, temporarily bind. When this occurs, a substrate-enzyme complex is formed and the reaction occurs.

Question 24

What is the lock and key model?

Answer 24

Proposed my Emily Fisher, the model suggests that the geometric shape of a substrate exactly fits the active site of the enzyme.

Question 25

What is the induced fit model?

Answer 25

Danil Koshland proposed that the shapes and charges of the substrate and enzyme are very close, but not exact fit, when the find each changes the shape of the other.

Question 26

What is the purpose of catalase?

Answer 26

An enzyme that breaks down hydrogen peroxide in aerobic organisms. The function of catalase is to decompose hydrogen peroxide to protect cells, tissues, and organs. Catalase is an extremely efficient enzyme with the ability to break down millions of hydrogen peroxide molecules per second. Catalase is important because it prevents hydrogen peroxide from causing oxidative stress in the cell. Oxidative damage includes - cell damage, mutated DNA, chronic inflammation, cancer, asthma etc.

Question 27

What is Rennin?

Answer 27

an enzyme that is synthesised in the stomach of some animals. Its role is to curdle or coagulate milk to ensure digestion and absorption of nutreints.

Question 28

How does temperature effect enzyme activity?

Answer 28

Enzymes will function at a specific temperature, the peak maximum level of enzyme activity is also known as the optimal temperature, when an enzyme stops working due to high temp it has denatured.

Question 29

How does pH affect enzyme activity?

Answer 29

Each enzyme has its own ideal pH and will not work unless it is in its ideal pH range.

Question 30

How does concentration affect enzyme activity?

Answer 30

the higher the substrate concentration, the greater the rate of enzyme reaction, until all available enzyme are being used to catalyse reactions. This is known as the saturation point.