1
Q
What is the proteome?
A
The proteome is the entire set of proteins expressed by a genome
2
Q
Why is the proteome larger than the no. Of genes? And where is this particularly true?
A
Because more than one protein can be produced from a single gene as a result of alternative RNA splicing
Particularly eukaryotes
3
Q
How can the set of proteins expressed by a given cell type vary?
A
The set of proteins expressed by a given cell type can vary over time and under different conditions.
4
Q
Eukaryotic cells have a system of internal membranes, which serve what purpose?
A
Increases the total area of membrane
5
Q
What is the Golgi apparatus?
A
The Golgi apparatus is a series of flattened membrane discs.
6
Q
What are lysosomes?
A
Lysosomes are membrane-bound organelles containing a variety of hydrolyses that digest proteins, lipids, nuclei acids and carbohydrates.
7
Q
What do vesicles do?
A
Vesicles transport materials between membrane compartments
8
Q
What is synthesised in the ER?
A
Lipids and proteins
9
Q
Where are lipids synthesised?
A
In the smooth endoplasmic reticulum (SER) and inserted into its membrane
10
Q
Where does the synthesis of all proteins begin?
A
The synthesis of all proteins begins in cytosolic ribosomes
11
Q
Where is the synthesis of cytosolic proteins completed?
A
In cytosolic ribosomes, remains in the cytosol
12
Q
Transmembrane proteins carry a signal sequence which…
A
Halts translation and directs the ribosome synthesising the protein to dock with the ER, forming RER.
13
Q
What happens after protein is synthesised and docks with the ER, forming RER
A
Translation continues after docking, and the protein is inserted into the membrane of the ER
14
Q
A
15
Q
Once synthesised proteins are in the ER what happens?
A
They are transported by vesicles that bud off from the ER and fuse with the Golgi apparatus
16
Q
What happens to proteins as they move through the Golgi apparatus
A
They undergo post-translational modifications.
17
Q
What is the major PTM
A
Addition of carbohydrate groups
18
Q
Vesicles that leave the Golgi apparatus do what?
A
Take proteins to the plasma membrane and lysosomes
19
Q
What do vesicles do within the cell?
A
Vesicles more along microtubules to other membranes and fuse with them within the cell
20
Q
Define proteins
A
Proteins are polymers of amino acid monomers
21
Q
Amino acids are classified by their R groups -what are they?
A
Basic (positively charged)
Acidic (negatively charged)
Polar
Hydrophobic
22
Q
What is the primary structure
A
The sequence in which the amino acids are synthesised into the polypeptide
23
Q
A
24
Q
What does hydrogen bonding along the backbone of the protein result in?
A
Regions of secondary structure - alpha helices, parallel or anti-parallel beta pleated sheets, or turns
25
26
What structure does the polypeptide fold into?
Tertiary
27
What is tertiary structure stabilised by ?
By interactions between r groups: hydrophobic interactions; ionic bonds; London dispersion forces; hydrogen bonds; disulfide bridges
28
Where does quaternary structure
In proteins with two or more connected polypeptide subunits
29
What is a prosthetic group?
Is a non-protein unit tightly bound to a protein and necessary for its function
30
What can influence interactions of the r groups
Temperature and pH
31
What is a ligand
A ligand is a substance that can bind to a protein
32
What happens as a ligand binds to a protein binding site and what does it result in?
As a ligand binds to a protein - binding site the conformation of the protein changes
This conformational change causes a function change in the protein.
33
Where do allosteric interactions occur?
They occur between spatially distinct sites.
34
35
36
What do allosteric proteins with multiple subunits show?
Show cooperativity in binding, in which changes in binding at one subunit alter the affinity of the remaining subunits
37
What do modulators do?
Regulate the activity of the enzyme when they bind to the allosteric site.
38
What follows binding of a modulator?
The conformation of the enzyme changes and this alters the affinity of the active site for the substrate
39
What is an example of cooperatively
The binding and release of oxygen in haemoglobin shows cooperativity
40
What can cause reversible conformational change in proteins?
A common form of PTM, the addition or removal of phosphate
41
What do protein kinases do?
Catalyse the transfer of a phosphate group to other proteins.
The terminal phosphate of ATP is transferred to specific r groups
42
What do protein phosphates do?
Catalyse the removal of phosphate groups from proteins
43
What does phosphorylation bring about? What else is regulated in this way?
Conformational change which can affect a protein's activity. The activity of many cellular proteas, such as enzymes and receptors, is regulated in this way
44
Are proteins activated or inhibited by phosphorylation?
Can be either or depending on the protein
45
What do regions of hydrophobic R groups allow?
They allow strong hydrophobic interactions that hold integral membrane proteins within the phospholipid bilayer
46
Some integral proteins are....
Transmembrane proteins
47
Describe peripheral membrane proteins, their characteristics, interactions etc.
Peripheral membrane proteins have hydrophilic R groups on their surface and are bond to the surface of membranes, mainly by ionic and hydrogen bond interactions.
Many peripheral membrane proteins interact with the surfaces of integral membrane proteins
48
What is the phospholipid bilayer?
Is a barrier to ions and most uncharged polar molecules
49
How do some molecules move across the phospholipid bilayer and what are 2 examples of such molecules?
A same small molecules such as oxygen or carbon dioxide can pass through the bilayer by simple diffusion
50
What is facilitated diffusion?
Is the passive transport of substances across the membrane through specific transmembrane proteins
51
To perform specialised functions, different sell types have...??
Different channel and transporter proteins
52
What is a key characteristic of most channel proteins in plants and animals?
HighIy selective
53
Describe the control of ligand gated vs voltage gated channels
Ligand gated channels are controlled by the binding of signal molecules
Voltage gated channels are controlled by changes in ion concentration
54
How do transporter proteins transport molecules across the membrane
Transporter proteins bind to the specific substance to be transported and undergo a conformational change to transfer the solute across the membrane
55
Describe the electrochemical gradient and its function
For a solute carrying a net charge the concentration gradient and the electrical potential difference combine to form the electrochemical gradient that determines the transport of the solute
56
Describe the sodium potassium pump
Ion pumps such as the sodium-potassium pump, use energy from the hydrolysis of ATP to establish and maintain ion gradients.
The sodium-potassium pump transports ions agains a steep concentration gradient using energy directly from ATP hydrolysis
It actively transports sodium ions out of the cell and potassium ions into the cell
3 sodium out
2 potassium in
57
Describe what happens in the sodium-potassium pump process
The pump has high affinity for sodium ions inside the cell
Binding occurs
Phosphorylation by ATP
Conformation changes
Affinity for sodium ion decreases
Fiction released outside cell
Dephosphorylation
Conformation changes
Potassium ions taken into cell
Affinity returns to start
58
59
What can hydrophobic signalling molecules do in order to bind to intracellular receptors
Can diffuse directly through the phospholipid bilayers of membrares
60
What are the receptors for hydrophobic signalling molecules
Transcription factors
61
The steroid hormones oestrogen and testosterone are examples of what
Hydrophobic signalling molecules
62
Where do steroid hormones bind to?
Specific receptors in the cytosol or the nucleus
63
Where do hydrophilic signalling molecules bind to
Bind to transmembrane receptors and do not enter the cytosol
64
Transmembrane receptors act as... By... Which
Signal transducers... Converting the extracellular ligand-binding event into intracellular signals, which alters the behaviour of the cell
65
Transducer hydrophilic signals often involve...
G-proteins or cascades of phosphorylation by kinase enzymes
66
Phosphorylation cascades allow...
More than one intracellular signalling pathway to be activated
67
Binding of the peptide hormone insulin to its receptor results in...??
2 an intracellular signalling cascade that triggers recruitment of glut 4 glucose transporter proteins to the cell membrane of fat and muscle cells.
68
Diabetes mellitus can be caused by
Failure to produce insulin (type1)
Loss of receptor function (type 2)
69
What effect does exercise have in subjects with type 2?
Exercise triggers recruitment of GLUT4, so can improve uptake of glucose to fat and muscle cells in subjects with type 2
70
What is meiosis
Meiosis is the division of the nucleus that results in the formation of haploid gametes from a diploid gametocyte
71
In diploid cells, chromosomes typically appear as
Homologous pairs
72
Describe meiosis one
The chromosomes, which have replicated prior to meiosis 1, each consist of 2 genetically identical chromatids attached at the centromere
The chromosomes condense and the homologous chromosomes pair up
Chiasmata form at points of contact between the non-sister chromatids of a homologous pair and sections of DNA are exchanged
This crossing over of DNA is random and produces genetically different recombinant chromosomes
Spindle fibres attach to the homologous pair are separated and move towards opposite poles
Cytokinesis occurs and two daughter cells form
73
74
Meiosis 2
Each of the 2 cells produced in meiosis 1 undergoes a further division during which the sister chromatids of each chromosome are separated
75
In most mammals, what determines development of male characteristics
The SRY gene on the Y chromosome
76
Heterogametic (XY) males lack most of the corresponding homologous alleles on the shorter (Y) chromosome
What can this result in?
This can result in sex-linked patterns of inheritance as seen with carrier females ( X^BX^b) and affected males ( X^bY)
77
In homoganetic females (XX) one of two X chromosomes present n each cell is randomly inactivated at an early stage of development
What does X chromosome inactivation prevent
A double dose of gene products which could be harmful to cells
As the X chromosome inactivated in each cell is random, half of the cells in any tissue will have a working copy of the gene in question
78
Define hermaphrodites
Hermaphrodites are species that have functioning male and female reproductive organs in each individual
79
What gametes do hermaphrodites produce, and do they partner?
They produce both male and female gametesand usually have a partner with which to exchange gametes
80
What is the benefit of hermaphroditism to the individual?
That if the chance of encountering a partner is an uncommon event, there is no requirement for that partner to be of the opposite sex
81
Under what circumstances can individuals of some species change sex?
As a result of size, competition, or parasitic infection
82
What can be adjusted in response to resource availability in some species?
Sex ratio of offspring
83
Give a sentence which summarises the costs and benefits of parental investment
Parental investment is costly but increases the probability of production and survival of young
84
Describe the circumstances under which r and k selection occur
R-selection tends to occur in unstable environments where the species has not reached its reproductive capacity
Whereas, k-selection tends to occur in stable environments
85
Successful courtship behaviour in birds and fish can be a result of what?
Species specific sign stimuli and fixed action pattern responses
86
Sexual selection selects for...?
Characteristics that have little survival benefit for the individual, but increase their chances of mating
87
What is female choice
Female choice involves females assessing honest signals of the fitness of males
88
Sampling should be carried out in a manner that...
Minimises impact on wild species and habitats.
89
In sampling, consideration must be given to...
Rare and vulnerable species and habitats that are protected by legislation..
90
What are 3 sampling techniques?
Point count, transect stilly, remote detection
91
What sampling methods should be used fer plants and other sessile or slow-moving organisms ?
Quadrats or transects
92
How can elusive species be sampled
Directly using camera traps
Or indirectly using Scat sampling or another indirect method
93
Define taxonomy
Involves the identification and naming of organisms and their classification who groups based on shored characteristics
94
Define phylogenetics
The study of the evolutionary history and relationships among individuals or groups of organisms.
95
What's a model organism and why are they useful
Model organisms are those that are easily studied or here been well studied
Info obtained from them can be applied to other species that are more difficult to study directly.
96
97
Define evolution
Evolution is the charge over time in the proportion of individuals in a population differing in one or more invented traits.
98
During evolution changes in allele frequency occur through which processes
(Identify 2 non -random and 1 random).
The non-random processes of natural and sexual selection
Random process of genetic drift
99
100
Summarise natural selection
Natural selection acts on genetic variation in populations
Populations produce more offspring than the environment can support
Individuals with variations better suited to their environment tend to survive longer und produce more offspring, breeding to pass on those alleles that conferred an advantage to the next generation
101
What is sexual selection
The non random process involving the selection of alleles that increase the individuals Chances s mating and producing offspring
102
Sexual selection may lead to -
Sexual dimorphism
103
Sexual selection can be due Te
Male-male rivalry and female choice
104
Define sexual dimorphism
105
Where selection pressures are strong...
The rate of evolution can be rapid
106
Why is genetic drift more important In small populations
As alleles are more likely Tu be lost from the gene pool
107
Genetic drift occurs when?
When chance events cause unpredictable fluctuations in allele frequencies from one generation to the next
108
The hardy Weinberg principle states that
In the absence of evolutionary influences, allele and genotype frequencies in population will remain constant over the generations.
109
Fitness is...
An indication of an individual’s ability to be successful at surviving and reproducing
It refers to the contribution made to a gene pool of the next generation by individual genotypes
110
Absolute fitness
Absolute fitness is the ratio between the frequency of individuals of a particular genotype after selection, to those before selection
111
Relative fitness
Is the ratio of the number of surviving offspring per individual of a particular genotype to the number of surviving offspring per individual of the most successful genotype
112
What is coevolution
Is the process by which two or more species evolve it response to selection pressures posed by each other
A change in traits of one species acts as a selection pressure one the other species
113
Costs of sexual reproduction
Males unable to produce offspring
Only half of each parent’s genome passed on to offspring disrupting successful parental genomes
113
Co evolution is frequently seen in pairs of species that have
113
Do the benefits of sexual reproduction outweigh the costs and why
Outweigh costs due to an increase in genetic variation in the population
113
What does genetic variation provide?
The raw material recruited for adaptation, giving sexually reproducing organisms a better chance of survival under changing selection pressures
114
Define parthenogenesis
114
What are examples of asexual reproduction in eukaryotes
114
Where is parthenogenesis more common
In cooler climates, which are disadvantageous to parasites ore regions of low parasite density or diversity
114
In asexual reproduction offspring can be produced …
More often and in larger numbers
114
Define vegetative reproduction
114
In what what can asexual reproduction be a successful reproductive strategy
As whole genomes are passed in from parent to offspring
Maintaining the genome of the parent is particularly advantageous in very narrow, stable niches or when re-colonising disturbed habitats
114
Asexually reproducing populations are not able to adapt easily to changes in their environment what happens to combat this
Mutations can occur that provide some degree of variation and enable some natural selection and evolution to occur
115
When is maintaining the genome of the parent particularly advantageous in asexual reproduction
In very narrow stable niches or when re colonising disturbed habitats
116
Describe the cytoskelton
The cytoskeleton gives mechanical support
and shape to cells
It consists of different protein structures
including microtubules, which are found in all eukaryotic cells
117
Microtubules are ...
Microtubules are hollow cylinders composed of the protein tubulin
118
microtubules are composed of
tubulin
119
microtubules radiate from
They radiate from the
microtubule organising centre (MTOC) or
centrosome.
120
Microtubules control ...
Microtubules control the movement of
membrane-bound organelles and
chromosomes
121
What does cell division require in relations to the cytoskeleton
Cell division requires remodelling of the
cytoskeleton
122
Formation and breakdown of microtubules involves ...
Formation and breakdown of microtubules
involves polymerisation and depolymerisation of tubulin
123
Adv. Higher Bio
flashcards
Decks in class (10)
# Cards
-
Proteomics, Protein Structure, Binding And Conformational change109
-
Biological field techniques31
-
evolution42
-
variation and sexual reproduction27
-
LAB TECHNIQUES6
-
Investigative Biology3
-
Exam based 25 (prelim topics only)3
-
Course Spec132
-
Parasitism73
-
Reproductive Behaviour And Mating Systems24
