B3 Living and Growing INCOMPLETE Flashcards Preview

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Flashcards in B3 Living and Growing INCOMPLETE Deck (85)
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1

define nucleus

contains the dna in the form of chromosomes.

2

define cell membrane fuction

hold the cell together and controls what goes in and out

3

what is a ribosome and where is it found?

it is where protiens are synthesised. found in animal cells

4

what is cytoplasm

a gel-like substance whre chemical reactions happen inside cells

5

what are mitrochondria and where are they found?

it is where most respriation reactions take place inside animal cells
musicle and lover clees need lots of respration so have lots of mitrochondria in their cells

6

what makes an plant cell different to an animal cell

it has chlorplasts cell wall and vacuole

7

define chloroplasts

green blobs where photosynthesis takes place

8

define cell wall

it is made of cellulose and supports the plant cell

9

define vacuole.

a relatively large structure that contains cell sap.( a weak sollution of sugar and salts

10

what do bacteria cells have.

cytoplasm, cell membrane, cell wall, dna strand, no chlorolast or mitrochondria

11

what do bacteria cell not have?

nucleus
chloroplatst
mitrochondria

12

what is a chromsome made up of/

dna coiled up

13

what is the shape of dna

a double helix on a sugar phosphate backbone

14

what are the four bases on dna

A C T G

15

what are the base pairs

AT (straght ones)
CG (curvy ones)
these are complimentray base-paring

16

define unicellular

orgainsims with just one cell (BACTERIA)

17

what is a chlorplasts made of

green pcgments that asorb energy. they are enbeded in disks like structures and arranged in stacks (thyiakoids)

18

what is a triplet codon?

a series on 3 base pairs.

19

what odes a triplet codon do.

codes for a spesific type of amino acid

20

what do amino acids produce

protiens. each protein has a different shape/ numer of amino acids. thus they all have different fuctions

21

what is they type of amino acid made dependnet on.

the order of the base pairs

22

who are watson and crick ad what did they do?

discovered the model for dna

23

how does dna replicate itself/

the cell divides. the doible helix "unzips"/ spearates.
new nucleotides (MRNA) join on using compilmetary base pairs.this makes and exact copy of the dna on the other stand
this results in two double stranded molecules of dna that are idnetical to the orginal.

24

how are protiens made?

by readingthe code in dna

25

define nucleotide

free floating in the nucleus. its a small molecue containing bases.

26

what is a gene

a section of dna that codes for a particular protein

27

what decides the order of amino acids in a proein/

the order of bases in a gene

28

WHAT IS RNA

DNA with no t but a u instead

29

how does protein synthesis happen

the dna unzips
RNA joins up with it
RNA coppies the gene
it is now MRNA a messenger
it goes to the ribosomes where the triplet condon/genes are read
the correct amino acid is produced and joined into a chain
amino acids released into cytoplasm where the join in chains to make a protien

30

what do ribosomes use.

code in dna that the mrna/rna has coppied.

31

why does the rna have to take coppies on the dna codes. and how?

the dna cont move out of the nucleus as its realy big so the code need to get from the nucleus to the ribosomes.the mrna acts as a messenger by copping the code.

32

what can dna control

a cell by controling protein production. they can switch off certain genes to stop procuctionin cells.

33

what do switched on genes determine/

the type of cell. there is a full set on genes i each cell but no all are needed. a mucsle cell doesnt need never, skin or bone genes so thye are tuened off but muclse cell procuction are turned on.

34

what is a mutation.

a change in the base order.
addition, removal or substutuional
this changes the triplet codon so the amino acid code had changes too and thus the protien too

35

how does mutatuon of dna occur

radiation and chemicals

36

name four types of protiens

enzymes
carrier molecules
hormones
structural enzmes

37

what is a carrier molecule

haemaglobin is used to transport oxygen around the blood.
used to transport smaler molecues

38

what is a hormone used for

to cary messages around the body. eg insulin is released into the blood by the pnacreas to regulate blood sugar levels.

39

what is a structual proteins job/

to be physically srtong.EG. collagen strengthen connective tissues ike ligaments and cartilage and tendons.

40

what is an enzymes job

a BIOLOGICAL CATALYST that controls chemical reactions in cells.

41

define catalyst

a substance that speeds up a reaction.it is not changed or used up in the reaction

42

every biological reaction has its own what....

enzyme designed spesifically for it. each enzymes is coded for by a differnt gene and has a unique shape for its job

43

define substarate

the moelcue changed in the reaction
the reactant

44

define active site

the part where the enzymes joins the substrate

45

enzymes have a high ....

high specifity for their substrate
usally only work with one substrate.

46

what has to work to allow the enzymes to work.

the substarte has to fit into the active site on the enzyme. otherwise it wont be catalysed.this is the lock and key mechanism theory.

47

what do enzymes need to work?

the correct temperature and PH

48

chaning the temp of a reaction alters the.....

the rate of an enzymes catalysed reaction
high temp= faster reaction and vice versa

49

what is an enzymes optimun temperature.

30-40 human enymes like 37 degrees

50

why does a higher temp cause a fater reaction

the more heat means enzymes and substrate has more energy.this makes them move about more so they collide more and react. HIGHER COLLISION RATE

51

what will happen if the reaction get too hot?

some of the bonds holding the enzymes together will break. the enyme will lose shape (denature) and the active site will not fit the substrate any more and it is not catalysed.

52

what happens if the Ph of an enzyme reaction is too high or low?

it interferes with the bonds holding the enzymes together.. this changes the active site and it denatures.

53

what is an enymes optimun PH?

often neurtral (7) but it can differ. pepsin works best at Ph2 and acidic conditions

54

what is Q10?

it shows the rate of reaction and how it changes with temperature

55

wats the formulae of Q10?

rate at higher temperature
-----------------------------------------
rate at lower temperature

56

what des at Q10 of 2 mean/show?

te rate doubles when the tep of raised by 10degres. a Q10 of 3 means it trebles/triples

57

what can mutations cause? in reprodcutive cells and body cells.

in reproductive cells the baby might develop abnormay or die
in body cells the mutated cells can multiply uncontralbly and invade the body(cancer)

58

how can mutations be beneficial?

it ca casue an improvemnt that gives the organism a survival advantages.this is natural selection and evolution at work

59

what is the main cause of mutaions. ad where do they come form and what do they cause.

sometime it ca happen spontaneously whn a chromosome doesnt copy properly
usaly due to radiation (xrays, ultraviolet light or radioactive substances)
or due to chmicals such as mutagen or carcinogens (cigarette smoke) these cause cancers

60

what are the advantages of being muticellular?

your bigger.
cell differnetation
more complex

61

how is being a bigger organiams helpful

you can travel further, get nurtiens in lots of ways, fewer thinks can eat or squash you.

62

how is having cell differentiation helpful/

you have differtn cells for certain jobs.ad they are adapted for their jobs

63

how is being a more comlex orgainsm good?

you can have specialised organswith different shapes ad behaviour.. this allows us to be adapted for or environemt particualry

64

define MITOSIS

making new cells for growth and repair.
cells reproducing by splitting to form two identical offspring

65

what are the5 stages of MITOSIS?

Interphase
Prophase
Metaphase IPMAT
Anaphase
Telephase

66

what happens at the first stage of MITOSIS?

the dna in the cell is replicated INTERPHASE

67

what happens at the scond stage of MITOSIS?

the dna coils into double armed chrosmosomes. these are exact coppies of the same dna (the left and right arm are the same) PROFASE

68

what happnes at the 3rd stage of MITOSIS?

the chosmomes line up at the center of the cells and divide as fibers pull them appart.
METAPHASE
the fibers apull the chromsomes to the opposite ends (poles) of the cell. ANAPHASE

69

what is the last stage of MITOSIS

the cytoplasm divides and you get two new cells containg the same genetic information. TELEPHASE

70

Define MEIOSIS

cell division to create sex cells/ gametes

71

where are gamets made.

in the ovaries and testes by meiosis

72

define diploid

body cells. two copies of each chromsome in the nucleus- one from each parent
Diploid = double

73

define haploid

gametes. only have one cipy of each cromsomes. so wen the egg and sperm combine they form a diploid cell
HAploid= HAlf

74

what the first stage of meiosis/

the dna replicates and curls up to form double armed chromosomes

75

whats the second stage of meiosis after the dna replicates?

the chromosomes arrange into pairs (23pairs / 46 alltogether)

76

what happens in meiosis after the chromosomes arrange into pairs?

in the first division the pairs split up nd move to oppostie poles of the cell.in each new cell there are no pairs just one of each. each new cell ends up with a mixture of your parents chromosomes but only half the usual number of chromosomes

77

wha are the basic stages of meiosis?

ne pair of chromosomes before division, they replicate. the cell thendivides into 4 (new sex cells)

78

what does fertilisation create?

a diploid cell called a zygote

79

what controlls of characterisitics of a zygote?

the combination of genes on its chrmosomes

80

whats an allele?

a gene code for differnt characterisitics

81

what type of cell os a sexcell?

haploid gamete

82

what is a sperms fuction?

to transport the males dna to the females egg

83

why do sperm have tails?

to help them swim, it used a flicly motion to move quickly

84

how do sperm have energy?

lots of mitochondria in the mid piece that produce lots of energy

85

how do sperm get through the membrane of the egg?

in the acrosome at the tip of the head enzymes are released that digest and get through the membrane