cell function

Question 1

what are organic substances?

Answer 1

chemical compounds that contain C-H atoms

(complex C molecules found in all organisms that supply the body with energy)

e.g. carbohydrate, protein, lipid

Question 2

what are biomacromolecules?

Answer 2

large, essential organic molecules, or polymers, that form the “building blocks of life” by providing structure and carrying out critical functions in all living organisms

THERE ARE FOUR MAIN TYPES:
carbohydrates (starch)
lipids (triglyceride)
nucleic acid (DNA)
protein (enzyme)

Question 3

what are inorganic substances?

Answer 3

chemical compounds that do not contain C-H chains

(simple molecules that are considered essential in the body for maintaining the structure of cells and tissues)

e.g. nutrients, oxygen / carbon dioxide gas, water

Question 4

whats diffusion?

Answer 4

the process where any materials (besides water molecules) move in and out of the cell

from a high concentration to a low concentration of the same substance.

Question 5

when does diffusion stop?

Answer 5

When equilibrium is reached.

This means all particles of that material has been dispersed, and no more movement occurs caused by the high concentration gradient.

Question 6

what impacts speed of diffusion?

Answer 6

temperature

heat increases because kinetic energy of particles increases

Question 7

whats facilitated diffusion?

Answer 7

a type of passive transport across a cell membrane that uses membrane proteins to move molecules down their concentration gradient, without the need for cellular energy

Question 8

whats the difference between diffusion and facilitated diffusion?

Answer 8

in simple diffusion, molecules move without the assistance of membrane proteins, whereas in facilitated diffusion, membrane proteins assist molecules in their movement downward.

Question 9

what are channel proteins?

Answer 9

proteins that create hydrophilic holes in cell membranes, facilitating the transport of molecules down the concentration gradient

Question 10

what are carrier proteins?

Answer 10

integral proteins that transport chemicals across the membrane both down and up the concentration gradient.
they have a binding site that allows particles to stick then the protein changes shape and the protein moves to release particle on other side

Question 11

whats osmosis?

Answer 11

the diffusion of only the solvent particles, which is usually water. In osmosis

water molecules move from high concentration to low concentration.

Question 12

isotonic

Answer 12

cell is normal, no water movement

Question 13

hypotonic

Answer 13

water movement into cell. cell swells and may burst

Question 14

hypertonic

Answer 14

water movement out of cell. cell shrivels and shrinks

Question 15

substances transported in diffusion

Answer 15

carbon dioxide
oxygen
water
food substances
wastes

Question 16

substances transported in osmosis

Answer 16

water

Question 17

substances transported in active transport

Answer 17

mineral ions and sugars (glucose)

Question 18

whats active transport

Answer 18

an energy driven process where substances move from a low to high concentration up a concentration gradient

Question 19

whats passive transport?

Answer 19

The transfer of materials across the membrane from a high to low concentration that does not require energy to move substances.

Question 20

what are isotonic, hypotonic and hypertonic applications of?

Answer 20

osmosis (which is passive transport)

Question 21

osmosis and diffusion are both …transport

Answer 21

passive

Question 22

whats endocytosis?

Answer 22

When a large particle or molecule needs to enter a cell, the cell engulfs it by forming a mouth-shape in its membrane, then brings the particle inwards.

There are two types of endocytosis: pinocytosis and phagocytosis.

Question 23

what are the two types of endocytosis?

Answer 23

pinocytosis= the intake of fluids and small dissolved molecules (cell drinking)

and phagocytosis = involves the engulfment of larger particles like bacteria or cellular debris (cell eating)

Question 24

whats exocytosis?

Answer 24

When the cell produces a large particle/s that is needed externally or some waste that need to remove.
A layer of the membrane is formed around the particle in the cytoplasm totally surrounding it then is driven to the surface to transport particles outward.

Question 25

whats photosynthesis?

Answer 25

A biochemical process that occurs in chloroplasts in plants. The chlorophyll, green pigment in the chloroplast is essential in this chemical reaction. This pigment absorbs light energy, which is transformed into usable energy for the plant which is glucose

Question 26

chemical word equation for photosynthesis

Answer 26

carbon+water+light→glucose+oxygen dioxide energy

Question 27

whats respiration?

Answer 27

a biochemical process that occurs in the mitochondria of the cell. The chemical compound glucose is broken down in the presence of oxygen to produce ATP. Carbon dioxide gas is expelled as waste

Question 28

types of respiration

Answer 28

aerobic and anaerobic

Question 29

whats aerobic respiration?

Answer 29

a metabolic process that converts glucose and oxygen into energy (ATP), carbon dioxide, and water -its the most efficient -continuous in plants and animals -occurs in mitochondria

Question 30

whats anaerobic respiration

Answer 30

This occurs when organisms cannot absorb oxygen gas because they do not live in an environment that has available oxygen

Question 31

Factors affecting the exchange of substances across membranes

Answer 31

Chemical factors - charged ions (cannot pass through, need channel proteins) - alcohol molecules (can pass through) - water (cannot pass through) Physical factors - The smaller the molecules, the faster they move across the membrane. - The bigger the molecule, the more they rely on endocytosis or exocytosis for transport.

Question 32

how to calculate SA:V of square

Answer 32

(square, each side 4x4) SA= 6x4x4 = 96 V= (lxhxh) =4x4x4 = 64 SA:V = 96 ÷ 64 = 1.5 = 1.5:1

Question 33

what are enzymes?

Answer 33

protein compounds that act as catalysts to speed up a reaction without getting involved in the rearrangement of atoms

Question 34

what are enzymes used for in metabolism?

Answer 34

To reduce the time it takes to breakdown complex molecules. This way the body can benefit from the metabolism effectively

Question 35

what happens when an enzyme is finished its function?

Answer 35

it will be recycled until it is structurally damaged

Question 36

whats the structure of an enzyme?

Answer 36

Each enzyme has a particular substrate that it binds to on its active site. This substrate is a separate molecule needed for metabolism. The body may produce them naturally or receive them from the food or supplements that they take.

Question 37

what are the two forms of metabolic reactions?

Answer 37

Catabolism = breakdown of large molecules into smaller ones for easy absorption of nutrients Anabolism = formation of large molecules, e.g. storage of starch into fat deposits for future energy supply

Question 38

how does an enzyme work?

Answer 38

For an enzyme to work, it must bind to a particular substrate in its active site. Once this occurs, an enzyme-substrate complex formation occurs. There are two theories: (1) Lock and Key model The active site has a fixed shape that exactly matches the substrate, like a key fitting into a lock. (2) Induced Fit model The active site changes shape to snugly fit the substrate, ensuring a secure and efficient reaction.

Question 39

what are the factors that influence enzyme activity?

Answer 39

1. substrate concentration The more substrate present in a reaction, the more enzymes are needed to speed up the reaction. 2. temperature Enzyme action slows down as temperature decreases due to slower kinetic energy between molecules. This leads to slower interaction between enzyme and substrate 3. pH Enzyme's ideal pH is where it is normally produced and/or used. Different parts of the body have different pH levels