topic 1 :key concepts in biology

Question 1

describe the cell structure of an animal cell

Answer 1

animal cell have a nucleus, cytoplasm, ribosomes, mitochondria and cell membrane

Question 2

describe the cell structure of a plant cell

Answer 2

have the same organelles as an animal cell but they also contain chloroplasts, cell wall and a vacuole.

Question 3

describe the cell structure of a bacterial cell.

Answer 3

bacteria cells contain some similaritiess with the plant and animal cells ( cell membrane and cytoplasm) however they have unique organelles such as: chromosmal dna, plasmid dna, flagella and cell wall.

Question 4

what is the difference between prokaryotic and eukaryotic?

Question 5

what are specialised animal cells?

Answer 5

specialised animal cells are cells that have undergone

Question 6

what are light microscopes used for?

Answer 6

used to study living cells and get a rough idea of the structure of the cells.

Question 7

what are elctron microscopes used for?

Answer 7

electon microscopes use a beam of electrons instead of light to get an image of up to 1,000,000 x its regular size. able yo clearly see all organelles and structures of all kinds of cells.

Question 8

how do you calculate magnification of microscope

Answer 8

magnification of eypiece lens * objective lens magnification

Question 9

what is resolution

Answer 9

the closest distance that can be distinguished between 2 points.

Question 10

what is the equation to calculate magnification?

Answer 10

magnification =size of image/real size of object

Question 11

what are enzymes

Answer 11

proteins that function as a biological catalyst

Question 12

what happens when an enzyme denatures?

Answer 12

the active sight of the enzyme is changed resulting to the enzyme being unable to react and break down the substrate

Question 13

how does temperature and ph affect an enzyme

Answer 13

temperature and ph affects wether the enzymes active site is able to remain the same shape, deciding the rate of reaction of wether the enzyme denatures

Question 14

how does enzyme concentration effect enzyme reaction rate

Answer 14

As the substrate concentration increases so does the rate of enzyme activity. An optimum rate is reached at the enzyme’s optimum substrate concentration

Question 15

what are carbohydrates, what enzyme breaks them down and where are they found?

Answer 15

carbohydrates are large molecules made from monosaccharides ( simple sugars). they are broken down by carbohydrase that are found in saliva, the pancreas and small intestine.

Question 16

what are proteins, what enzyme breaks them down and where are those enzymes found?

Answer 16

proteins are large molecules made from amino acids. protease is the enzyme that breaks down proteins. it is found in the stomach, pancreas and small intestine.

Question 17

what are lipids, what breaks them down and where are these enzymes found ?

Answer 17

lipids are large molecules made from smaller units of fatty acids and glycerol.
digestive enzymes lipase break them down which are produced in the pancreas and small intestine

Question 18

what is diffusion?

Answer 18

Diffusion is the passive transport in cells, where substances move from an area of high concentration to an area of low concentration.

Question 19

what is osmosis?

Answer 19

Osmosis is the diffusion of water molecules, from a region of higher concentration to a region of lower concentration, through a selectively permeable membrane.

Question 20

what is active transport?

Answer 20

Active transport is the movement of substances against a concentration gradient using energy. (low to high concentration)