topic 1, key concepts

Question 1

Acrosome

Answer 1

an organelle in the tip of a sperm that contains enzymes which digest the cell cell membrane

Question 2

active site

Answer 2

a specific region on an enzyme where the substrate binds and the reaction takes place

Question 3

active transport

Answer 3

the movement of substances from a low concentration to a higher concentration ( against the concentration gradient), with the use of energy from respiration

Question 4

carbohydrases

Answer 4

enzymes that break down carbohydrates into simple sugars

Question 5

carbohydrates

Answer 5

a large molecule that is synthesised from simple sugars.

Question 6

cell

Answer 6

the basic building block of all living organisms

Question 7

cell membrane

Answer 7

a partially permeable membrane barrier that surrounds the cell

Question 8

cell wall

Answer 8

an outer layer made of cellulose that strengthens plant cells

Question 9

chloroplasts

Answer 9

an organelle that is the site of photosynthesis

Question 10

chromosome

Answer 10

a long, coiled molecule of DNA that carries genetic information in the form of genes

Question 11

cilia

Answer 11

hair like structures found on ciliated epithelial cells which waft substances across the surface of the tissue in one direction

Question 12

ciliated epithelial cell

Answer 12

a type of epithelial cell that lines the surface of structures such as the respiratory tract and uterus.

Question 13

concentration gradient

Answer 13

the difference in concentration between two areas

Question 14

denaturation

Answer 14

upon high exposure to high temperatures, or extremes of pH, the permanent change in the shape of an enzymes active site that prevents the binding of a substance

Question 15

diffusion

Answer 15

the spreading of particles from a high concentration to a lower concentration (down their concentration gradient

Question 16

diploid cell

Answer 16

a cell which contains two copies of each chromosome

Question 17

egg cell

Answer 17

a specialised female sex cell involved in reproduction

Question 18

electron microscope

Answer 18

a type of microscope that uses a beam of electrons, focused using magnets, to produce an image of a specimen. it has greater magnification and resolution than a light microscope

Question 19

enzyme

Answer 19

a biological catalyst that increases the rate of reactions in living organisms

Question 20

eukaryotic cell

Answer 20

a type of cell found in plants and animals that contains a nucleus

Question 21

flagella

Answer 21

a long hair like structure, found on bacterial cells that is used for cell movement

Question 22

haploid cell

Answer 22

a cell that contains a single copy of each chromosome

Question 23

light microscope

Answer 23

a type of microscope that uses a series of lenses to magnify the visible light reflecting off a specimen. It has lower magnification and resolution than an electron microscope

Question 24

lipases

Answer 24

enzymes that break down lipids into fatty acids and glycerol

Question 25

lipid

Answer 25

a large molecule that is synthesised from fatty acids and glycerol

Question 26

lock and key hypothesis

Answer 26

a theory that describes how substrates must be the correct shape to fit the active site of an enzyme

Question 27

magnification

Answer 27

the number of times bigger an image appears compared to the original object. image size = magnification x real size

Question 28

micrometre

Answer 28

a qualitative unit of length. 1 um = 1x10^-6 meters

Question 29

millimetre mm

Answer 29

a qualitative unit of length. one millimetre is equal to x10^-3 metre

Question 30

mitochondria

Answer 30

an organelle that is the site of respiration

Question 30

nanometre

Answer 30

x10^-9

Question 31

nucleus

Answer 31

an organelle found in most eukaryotic cells that contains the genetic material of the cell and controls the activities of the cell

Question 32

organelle

Answer 32

a specialised structure found inside a cell

Question 33

osmosis

Answer 33

the diffusion of water molecules from a region of high water concentration to a region of lower water concentration across a partially permeable membrane.

Question 34

percentage change in mass

Answer 34

the proportion of the mass of a substance that has changed over a set period. percentage change in mass = final mass - initial mass/ initial mass x100

Question 35

pictometre

Answer 35

x10^-12

Question 36

plasmid

Answer 36

loops of dna found in the cytoplasm of prokaryotic cells

Question 37

prokaryotic cells

Answer 37

a type of cell found in bacteria that does not contain a nucleus

Question 38

protease

Answer 38

enzymes that break down proteins into amino acids

Question 39

protein

Answer 39

a large molecule that is synthesised from amino acids

Question 40

rate of reaction

Answer 40

the speed at which reactants are converted into products

Question 41

resolution

Answer 41

the smallest distance between two objects that can be distinguished

Question 42

ribosomes

Answer 42

sub - cellular structures that are the site of protein synthesis

Question 43

specialised cell

Answer 43

a cell that has a structure which makes it adapted to its function

Question 44

specificity

Answer 44

describes the ability of an enzyme to catalyse only a particular reaction or set of reactions in which a specific substrate fits the active site of the enzyme

Question 45

sperm cell

Answer 45

a specialised male sex cell that is involved in reproduction

Question 46

vacuole

Answer 46

an organelle found in plant cells which stores cell sap and supports the cell