M1 Q2 - Cell Functions

Question 1

Diffusion

Answer 1

Diffusion is the movement of molecules from a high concentration to low concentration until equilibrium is reached. No energy input is required.

Question 2

Facilitated diffusion

Answer 2

The process of diffusion with the help of certain proteins known as carrier and channel proteins

Question 3

Osmosis

Answer 3

Osmosis is the process by which water moves from a region of high water concentration to a region of low water concentration. It requires no energy.

Question 4

Osmosis types

Answer 4

• Hypotonic
• Hypertonic
• Isotonic

Question 5

Hypotonic

Answer 5

Greater concentration of solute inside the cell

Water goes into the cell, cell could get bigger and burst

Question 6

Hypertonic

Answer 6

Greater concentration of solute outside the cell.

Water leaves the cell. Cell will shrivel and dehydrate

Question 7

Isotonic

Answer 7

Concentration inside cell is equal to that of the solution.

Cell is at equilibrium

Question 8

Active Transport

Answer 8

Active transport moves molecules from low to high concentration using energy and carrier proteins

Question 9

Active Transport types

Answer 9

• Endocytosis
• Exocytosis

Question 10

Endocytosis

Answer 10

Moves large molecules into the cell using energy. The cell membrane engulfs particles, bringing them inside.
- Phagocytosis: engulf solid (still eating)
- Pinocytosis: engulf fluids (cell drinking)

Question 11

Exocytosis

Answer 11

Exocytosis transport substances by fusing a vesical with the cell membrane to release its content outside the cell

Question 12

Cell requirements

Answer 12

• cells need to obtain nutrients in the form of organic substances such as glucose, amino acids, fatty acids and vitamins
• cells also need inorganic nutrients such as gases (oxygen and carbon dioxide), minerals and water

Question 13

Photosynthesis

Answer 13

Photosynthesis is process used by autotrophs, to produce their own glucose. Plants used light energy, trapped by chlorophyll, to break down carbon dioxide and water, to produce glucose and oxygen

carbon dioxide + water —> (light energy + chlorophyll) glucose + oxygen

Question 14

Cell respiration

Answer 14

The process of producing energy is called respiration. When glucose and oxygen combine in the process of aerobic cellular respiration, energy is produced along with water and carbon dioxide.

Glucose + oxygen —> carbon dioxide + water + energy

Question 15

Enzymes

Answer 15

Enzymes are composed of protein molecules that are often folded to create a particular chemical ‘shape’

Enzymes act as biological catalysts, they occur inside cells or are secreted by the cell

Question 16

Enzymes proteins

Answer 16

• Catalase
• Amylase
• Pepsin
• Trypsin

Question 17

Lock and key model

Answer 17

The model describes the enzyme as a ‘key’, the substrate ‘lock’. When the key interacts with the lock, the lock changes shape, but the key remains unchanged for continued use.

Question 18

Factors that affect enzymes

Answer 18

• Temperature
• pH level
• Substrate concentration

Question 19

Effect of pH

Answer 19

Each enzyme works best at a certain pH. If the PH is too low or too high, the enzyme could denature.

Question 20

Effect of temperature

Answer 20

As temperature increases, enzyme activity increases. The best temperature is called the optimum temperature. If it gets too hot, the enzyme could denature.