Unit 1 + 4 Flashcards
1
Q
what is a biological molecule
A
any molecule that is present in living organisms
2
Q
when do hydrogen bonds form
A
when a slightly positive and slightly negative charge come close
3
Q
what does bose mean in a molcule
A
that it is a sugar
4
Q
what shape is fructose
A
pentagon
5
Q
give 3 examples of disaccharides
A
maltose
sucrose
lactose
6
Q
give similarities of lactose and lactulose
A
- both have glycosidic bonds
- both are formed from condensation reactions
7
Q
give a difference between lactose and lactulose
A
- lactulose contains fructose but lactose contains glucose
8
Q
give 3 examples of polysaccharides
A
starch
cellulose
glycogen
9
Q
what makes up fungal cell walls
A
chitin
10
Q
give 2 advantages to starchs structure
A
- spiral shaped so its more compact and easier to store
- its a branched molecule and more branches mean more points enzymes can attach
11
Q
give differences between starch and cellulose
A
- starch is made of alpha glucose molecules
- cellulose is made of beta glucose
- starch is helix shaped and cellulose is straight
12
Q
what are amylose and amylopectin made of
A
alpha glucose because starch is made from it
13
Q
why is glycogen structure benefical for its use
A
- made of alpha glucose
- branched which gives it easy access to stored energy
14
Q
how is the strucure of starch similar to cellulose
A
- both made from monosaccharides
- they both contain glycosidic bonds
15
Q
what is a reducing sugar
A
a sugar that can donate electrons
16
Q
what happens in benedicts test when a reducing sugar is present
A
an isoluble red precipitate forms
(which absorbs light)
17
Q
advantages to lipids
A
- good energy store
- good for insulation
18
Q
what are the 2 types of lipids
A
- triglycerides
- phospholipids
19
Q
what are proteins used for
A
- enzymes
- antibodies
- hormones
- structure (collagen)
20
Q
what is the primary strucute of a protein
A
the sequence of amino acids
21
Q
what is the secondary structre of proteins
A
the formation of hydrogen bonds
22
Q
what is the tertiary structure of proteins
A
when the secondary structure folds up into a 3d structure
23
Q
what are the 2 different types of proteins
A
globular
fibrous
24
Q
whats the difference between globular and fibrous proteins
A
globular - globe like structre
fibrous - long intertwined chains
25
what are the 3 types of tissues in the digestive sytem
- muscular
- glandular
- epithelial
26
where does mechanical digestion take place
the mouth
27
where does chemical digestion take place
- salvilary glands
- stomach
- small intestines
28
whats its called when food moves down the oesphagus
peristalisis
29
what must happen for fats (triglycerides) to be digested
they are not water soluble so they must be emulsified
30
what type of bond is found in a triglyceride
ester
31
whats the difference between competitve and non - competitve inhibtion
- competitive binds to active site
- non competive changes shape
32
how can you tell if a substrate is comp or non comp
- increase the concentration of substrate
- eventually non comp will get broken down
33
what is the genome
all the genes in an individual
34
what is a gene
the basic unit of hereditary information which is the sequence of bases in DNA
35
what are the 4 organic bases for DNA
guanine
cytosine
adenine
thymine
36
what happens to thymine in RNA
its replaced with uracil
37
which 2 bases are pyrimidines
cYtosine and thYmine
38
which 2 bases are purines
guanine and adenine
39
whats the difference between pyrmidines and purines
pymrimidines have a one ring structure
purines have a two ring structure
40
how is DNA a stable molecule
its phosphodiester backbone protects it from the more chemically reactive bases
41
what is the function of DNA
to pass genetic information from cell to cell
42
what does DNA helicase do
breaks down the hydrogen bonds and unwinds the double helix
43
what does DNA polymerase do
joins the adjacent nucleotides with a phosphodiester bond
44
why do we need energy
- to maintain homeostasis
- muscle contractions
- metabolic reactions like protein synthesis
45
what is an example of a catabolic reaction
digestion
46
why can ATP be considered immediate energy
because so little is stored and its released in maneagble loads
47
roles of ATP in plant cells
- metabolic reactions
- active transport
- growth
48
why is water essential
- good solvent
- required for photosynthesis
- metabolic reactions
49
similarities between RNA and DNA
- both have nucleic acids
- both have phosphate
- both polymers
50
what is transcription
where the DNA gene is copied into messenger RNA
51
where does transcription take place
the nucleus
52
whats translation
where the mRNA is used to join the correct sequence of amino acids
53
what is the genetic code
- degenerate
- non overlapping
- universal
54
what does degenerate mean
when amino acid can be coded for mutiple codons
55
what are introns
non coding sections of DNA
56
what are exons
base sequence coding for polypeptides
57
what does universal mean in the genetic code
almost every organism uses the same code
58
what does non overlapping mean in the genetic code
there is no overlap between triple codes
59
what is a zygote
a fertilised egg
60
what is the advantage of longer chromosome
the greater number of chiasmata
which means new combination of allelels
61
what is chiamasta
when chromosomes wrap around each other
62
what is genetic diversity
genetic differences between indivduals within a population
63
what is allele frequency
how often a particular allele occurs within a population
64
how can you increase genetic diversity
- migration brings new alleles
- mutations makes new alleles
65
how can you decrease genetic diversity
- selective breeding
- bottle neck effect
66
what is the bottle neck effect
when the population number is dramatically decreased due to natural disasters
67
what is the founder effect
when a few members of a population start a new population
68
define evolution
to evolve and change overtime of long periods
69
what is selection pressure
a driving force which causes evolution
70
define species
a group of organisms that can interbreed and create fertile offspring
71
what is phylogeny
the evolutionary relationship between organisms
72
what is a protein for respiaration
cytochrome C
73
what is biodiversity
the number and variety of living organsims present in an area
74
what is species diversity
how many different species are present in an area and how many there are
75
what is species richness
number of different species present
76
what is species eveness
how balanced the number of each species is
77
what is genetic diversity
how many variations there in the genetic code
78
what is discontinous variation
clearly defined categories like race, hair colour, eye colour
79
what is continous variation
can be within a range like height, age and hair length
80
name 3 defence mechanisms and how they defend
mucus - traps foreign bodies
stomach - contains stomach acid
tears - contain lysozomes
81
what is a phagocyte
type of WBC which engulfs and digests pathogens
82
where are B and T lymphocytes produced
bone marrow in stem cells
83
what do B lymphocytes produce
antiBodies
84
difference between B and T lymphocytes
B mature in bone marrow
T mature in thymus
85
what do T cells do
release signalling molecules to stimulate an immune response
86
what do T killer cells do
attack and destroy our own body cells that are infected with pathogens
87
roles of T cells
- stimulates phagocytosis
- stimulate B cells to divide and become plasma cells
88
what do plasma cells do
secrete antibodies directly
89
what is agglutinate
clumping of pathogens together which makes phagocytosis easier
90
what is meant by primary immune response
the intial response caused by a first infection
91
what is meant by a secondary response
a more rapid response caused by a second infection by the same pathogen
92
what is passive immunity
when antibodies are passed to an individual e.g breastfeeding or injections
93
what is active immunity
when an active body actively produces antibodies
94
how is a phosphodiester bond formed between nucleotides
- condensation reaction means loss of water
- between phosphate and deoxyribose
- this is catalysed by DNA polymerase
95
how is RNA produced
- nucleotides form complementary base pairs
- phospodiester bonds form
- by RNA polymerase
96
as forest area was cleared the species diversity of insects decreased, why
- decrease in variety of plants
- fewer habitats
- decrease in variety of food
97
why is a larger sample better
it produces a more reliable mean
98
describe the absorption of amino acids in the ileum
- facilitated diffusion of amino acids into a cell via carrier proteins
- co transport
- sodium ions actively transported from cell to blood
- this creates a diffusion gradient
99
what do plasma cells do
secrete antibodies
100
what holds antibodies together
disulphide bridges
