B3 Living and Growing INCOMPLETE Flashcards
(85 cards)
1
Q
define nucleus
A
contains the dna in the form of chromosomes.
2
Q
define cell membrane fuction
A
hold the cell together and controls what goes in and out
3
Q
what is a ribosome and where is it found?
A
it is where protiens are synthesised. found in animal cells
4
Q
what is cytoplasm
A
a gel-like substance whre chemical reactions happen inside cells
5
Q
what are mitrochondria and where are they found?
A
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
Q
what makes an plant cell different to an animal cell
A
it has chlorplasts cell wall and vacuole
7
Q
define chloroplasts
A
green blobs where photosynthesis takes place
8
Q
define cell wall
A
it is made of cellulose and supports the plant cell
9
Q
define vacuole.
A
a relatively large structure that contains cell sap.( a weak sollution of sugar and salts
10
Q
what do bacteria cells have.
A
cytoplasm, cell membrane, cell wall, dna strand, no chlorolast or mitrochondria
11
Q
what do bacteria cell not have?
A
nucleus
chloroplatst
mitrochondria
12
Q
what is a chromsome made up of/
A
dna coiled up
13
Q
what is the shape of dna
A
a double helix on a sugar phosphate backbone
14
Q
what are the four bases on dna
A
A C T G
15
Q
what are the base pairs
A
AT (straght ones)
CG (curvy ones)
these are complimentray base-paring
16
Q
define unicellular
A
orgainsims with just one cell (BACTERIA)
17
Q
what is a chlorplasts made of
A
green pcgments that asorb energy. they are enbeded in disks like structures and arranged in stacks (thyiakoids)
18
Q
what is a triplet codon?
A
a series on 3 base pairs.
19
Q
what odes a triplet codon do.
A
codes for a spesific type of amino acid
20
Q
what do amino acids produce
A
protiens. each protein has a different shape/ numer of amino acids. thus they all have different fuctions
21
Q
what is they type of amino acid made dependnet on.
A
the order of the base pairs
22
Q
who are watson and crick ad what did they do?
A
discovered the model for dna
23
Q
how does dna replicate itself/
A
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
Q
how are protiens made?
A
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
