Year 9 assessment revision (CB1-Key concepts in biology)

Question 1

what is the active site

Answer 1

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

Question 2

what is active transport

Answer 2

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

Question 3

carbohydrases

Answer 3

enzymes which brake down carbohydrates into simple sugars

Question 4

carbohydrate

Answer 4

a large molecule that is synthesised from simple sugars

Question 5

cell

Answer 5

the basic building block of all living organisms

Question 6

cell membrane

Answer 6

a partially permeable barrier that surrounds the cells

Question 7

cell wall

Answer 7

an outer layer made of cellulose that strengthens the plant cells

Question 8

chloroplast

Answer 8

an organelle that is the site of photosynthesis

Question 9

chromosome

Answer 9

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

Question 10

cilia

Answer 10

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

Question 11

ciliated epithelial cell

Answer 11

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

Question 12

concentration gradient

Answer 12

the difference in concentration between two areas

Question 13

denaturation

Answer 13

when the active site of an enzyme is permanently changed ,due to exposure to high temperatures or extremes of pH, preventing the binding of a substrate

Question 14

diffusion

Answer 14

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

Question 15

diploid cell

Answer 15

a cell that contains two copies of each chromosome (a full set of chromosomes)

Question 16

egg cell

Answer 16

a specialised female sex cell involved in reproduction

Question 17

electron microscope

Answer 17

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

Question 18

enzyme

Answer 18

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

Question 19

Eukaryotic cell

Answer 19

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

Question 20

flagella

Answer 20

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

Question 21

haploid cell

Answer 21

a cell that contains a single copy of each chromosome (half the number of chromosomes)

Question 22

light microscope

Answer 22

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 that of an electron microscope

Question 23

lipases

Answer 23

enzymes that break down lipids into fatty acids and glycerol

Question 24

lipid

Answer 24

a large molecule that is synthesised from fatty acids and glycerol

Question 25

lock and key hypothesis

Answer 25

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

Question 26

magnification

Answer 26

the number of times bigger an image appears compared to the original object, calculated using the formula: image size = magnification x real size

Question 27

micrometre (μm)

Answer 27

a quantitative unit of length. One micrometre is equal to x10^-6 metre

Question 28

millimetre (mm)

Answer 28

a quantitative unit of length. One millimetre is equal to x10^-3 metre

Question 29

mitochondria

Answer 29

an organelle that is the site of respiration

Question 30

nanometre (nm)

Answer 30

a quantitative unit of length. One nanometre is equal to x10^-9 metre

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, calculated using: percentage change in mass = final mass - initial mass ÷ initial mass x100

Question 35

picometre (pm)

Answer 35

a quantitative unit of length. One picometre is equal to x10^-12 metre

Question 36

plasmid

Answer 36

loops of DNA found in the cytoplasm of prokaryotic cells

Question 37

prokaryotic cell

Answer 37

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

Question 38

proteases

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 structure 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 an 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