Biochemistry Flashcards
(103 cards)
0
Q
What is static biochemistry?
A
The study of substances forming living cells and tissues as well as those administrating the biochemical processes
1
Q
What is biochemistry?
A
The study of the chemical processes,transformations and their regulation in living organisms
2
Q
What is dynamic biochemistry?
A
The study of transformations of compounds in living cells/organisms
3
Q
What is regulatory biochemistry?
A
The study of regulation of biochemical processes in living organisms
4
Q
What are proteins?
A
Highly organised biopolyners formed from the alpha-L-amino acid residues bound to each other by peptide bonds
5
Q
Name the amino acids that are non-polar aliphatic alpha-radicals?
A
Glycerine Alanine Proline Valine Leucine Isoleucine Methionine
6
Q
Name the amino acids that aromatic aloha-radicals?
A
Phenyl-alanine
Tyrosine
Tryptophan
7
Q
Name the amino acids that are polar uncharged radicals?
A
Cysteine Threonine Serine Asparagine Glutamine
8
Q
Name the amino acids that are positively charged alpha-radicals?
A
Lysine
Arginine
Histidine
9
Q
Name the amino acids that are negatively charged alpha-radicals?
A
Aspartic acid
Glutamic acid
10
Q
Describe the secondary structure of proteins?
A
Alpha-helix : each step contains 3.6 amino acid residues forming hydrogen bonds between each other.
Beta pleated sheets: formed by hydrogen bonds between NH and CO-groups of neighbouring parallel or more often anti-parallel chains
11
Q
What is the quaternary structure of a protein (haemoglobin)?
A
Four 16kDa subunits form single protein
12
Q
What is a protein structural domain?
A
An element of overall structure that is self-stabilising and often folds independently of the rest of the protein chain.
13
Q
List the 9 protein functions
A
Catalytic Transport Regulatory Hormonal Immune Nutrition Structural Energetic Genome
14
Q
What are the 6 classes enzymes are divided into?
A
Oxidoreductases Transferase Hydrolase Liases Isomerase Ligases
15
Q
What do oxidoreductase catalyse?
A
Oxidation / reduction reactions
16
Q
What do transferase catalyse?
A
Transfer groups of atoms from one molecule to another
17
Q
What do hydrolyse catalyse?
A
Reactions associated with hydrolysis
18
Q
What do liases catalyse?
A
Attach functional groups to pi-bonds
19
Q
What do isomerases catalyse?
A
Catalyse reactions of isomerisation
20
Q
What do ligase catalyse?
A
Reactions of biosynthesis
21
Q
How many digits does a EC number contain?
A
4
22
Q
What is the speed of the enzyme reaction described by?
A
The Michelis-Menthen equation
23
Q
What is isosteric inhibition?
A
When the inhibitor competes with the substrate for interaction with the active site of the enzyme
24
What is absolute substrate specificity?
When the enzyme can only convert one substrate
25
What is absolute group specificity?
When the enzyme recognises specific group of atoms which applies to several substrates
26
What are Iso-enzymes?
Enzymes of different but similar structure which perform the same reactions
27
What are muti-enzyme systems?
Systems containing several enzymes which catalyse consequent conversion of the same substrate
28
What is nucleoproteins?
Prosthetic groups are nucleic acids
29
What are glycoprotein?
Prosthetic group are carbohydrates
30
What are lipoprotein?
Prosthetic group are lipids
31
What are chromoproteins?
Prosthetic group are coloured compounds like heme, derivatives of vitamin B2
32
What are phosphoproteins?
Prosthetic group is H3PO4
33
What are metalloproteins?
Prosthetic groups are metal cations
34
What structure is DNA double helix?
Secondary structure of nucleic acids
35
What is the ratio range for (G+C)/(A+T) in Chargaffs rule?
0.54-0.94 and is always less than 1
36
What is the tertiary structure of nucleic acids?
Super-helices
37
What is the function of nucleic acids?
The storage and transfer if genetic information
38
What are carbohydrates?
Straight-chain aldehydes or ketones with many hydroxyl groups added, usually one on each carbon atom that is not part of the aldehyde or ketone functional group
39
What are carbohydrates containing aldehyde group called?
Aldoses
40
What is a carbohydrate contains ketone group called?
Ketoses
41
What is oligosaccharides?
Carbohydrate contains 3-6 monosaccharide units
42
What are the five different lipids?
```
Triacylglycerols or fats
Phospholipids
Sphingolipids
Cardiolionins
Steroids
```
43
What is the most important feature of a bio membrane?
That it is selectively permeable structure
44
What is diffusion?
Transport of molecules down a concentration gradient
45
What is facilitated diffusion?
Uses membrane proteins channels to allow charged molecules to diffuse in and out of the cell. Small ions like K+, Na+ and Cl-
46
What is facilitated diffusion limited by?
The number of protein channels available
47
What does active transport require?
Requires energy to transport the molecules form one side of the membrane to the other, can take molecules up their concentration gradient. Also limited by number of protein transporters present
48
What are receptors?
Proteins on the cell membrane that bind to specific molecules such as growth or pro-apoptotic factor,neurotransmitter,hormone,pathogen molecular pattern or other substances, and initiate cellular responses to ligands. Ligands induced changes in behaviour of receptor proteins result in physiological changes that constitute the biological actions of he ligands.
49
What are transmembrane receptors?
Proteins that span the thickness of the plasma membrane of the cell, with one end of the receptor outside (extracellular domain) and one inside (intercellular domain) the cell. Also a transmembrane domain located between two other domains and interacts with the cell membrane
50
What do tyrosine kinases receptors do?
These receptors detect ligands and propagate signals via the tyrosine kinase of their intracellular domains
51
Give a example of a tyrosine kinase receptor?
Insulin receptor
52
What are ionotropic receptors?
These receptors impact membrane transport of ions
53
Name some ionotropic receptors
Nicotinic acetylcholine receptors
Glycine receptors
Glutamate receptors
54
What are pattern recognition receptors?
Receptors that recognise molecular patterns of pathogens an sunshine inflammation and innate immune responses
55
What are transcription factors?
Located in the cytosol or nucleus and regulate gene expression upon interaction with their ligand
56
Name a three steroid receptors?
Oestrogen receptors
Glucocorticoid receptors
Vitamin D receptor
57
Name a thyroid hormone receptor?
Retinoids receptor
58
What is single transduction?
Any process by which a cell converts one kind of signal or stimulus into another. Process refers to a sequence biochemical reactions inside the cell carried out by enzymes and linked through second messengers
59
How long do signal transduction processes usually take?
Milliseconds to a few seconds
60
What is the goal of signal transduction?
Administration of the cell cycle and cell differentiation m. They regulate growth, programmed cell death and differentiation of cells
61
What is the cell cycle?
A series of events in a eukaryotic cell between one cell division and the next
62
What are the four phases of the cell cycle?
G1 phase, S phase , G2 phase known as interphase and M phase with consists of mitosis and cytokinesis
63
What do signalling events start with?
Interaction of ligand with target transmembrane or nuclear receptor
64
What do signalling cascade involve?
Phosphorylation reactions performed by protein kinase enzymes
65
ATP is used as a donor of phosphoric acid, used for the esterification of what?
Threonine , serine or tyrosine residues of substrate protein
66
What do kinase recognise?
Target amino acid residues when it is surrounded by certain proteins
67
What is metabolism?
Is a biochemical modification of substances in living organisms and cells. Where nutrients are processed into biochemical tools and structure needed to maintain a living state
68
What are the two divisions of metabolism?
Anabolism and catabolism
69
What is anabolism?
Is when a cell uses energy and reducing power to construct complex molecules and perform other life functions such as creating cellular structure
70
What is catabolism?
When a cell breaks down complex molecules to yield energy and reducing power
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What is a metabolic pathway?
Complex sequences of controlled chemical reactions usually enzymatic reactions
72
What is the brief scheme of reaction of glycogenolysis?
Hormone or mediator>cAMP>protein kinase A>phosphorylase kinase>glycogen phosphorylase>removes terminal residues of glucose by attaching a phosphate group breaking glycosidic bond between terminal residues
73
List the sequence in the Krebs cycle?
Pyruvate>acetylCoA>citrate>isocitrate>alpha-ketoglutarate>succinylCoA>succinate>fumarate>malate>oxaloacetate
74
What is pentode phosphate pathway?
Additional carbohydrate metabolism cascade which helps two omit several stages of glycolysis
75
Why is the pentose phosphates pathway used for?
Minimise ATP consumption
| Increase ATP production
76
When is the pentose pathway activated?
When glycolysis is overloaded
77
What is catabolism of triacylglycerol?
Degredation of triacylglycerol by lipases into fatty acids and glycerol
78
What is catabolism of proteins performed by?
Protease enzymes
79
What are the two groups are protease enzymes divided into?
Endopeptidases
| Exopeptidase
80
What do endopeptidase do?
Cleave the internal peptide bonds of the substrate protein
81
Give examples of endopeptidases?
Pepsin, trypsin,chimotrypsin, elastase
82
What do carboxy Exopeptidase do?
Carboxy peptidases remove the C-terminal amino acid of the protein
83
What do aminopeptidase do which are Exopeptidase?
Remove the N-terminal amino acid of the protein
84
What is the sequence of protein catabolism?
Endopeptidases split protein into smaller fragments which further cleaved by Exopeptidase unto then into di/tripeptidase by di/tripeptides
85
What happens to released amino acids?
Gut her metabolised or re-used for synthesis of cellular proteins
86
Name the five deaminations?
Reductive deamination
Intramolecular deamination
Hydrolytic deamination
Oxidative deamination
87
Name the three decarboxylation
Alpha-decarboxylation
Omega-decarboxylation
Decarboxylation associated with transamination
88
Deamination produces two product what is the product that they all produce?
NH3
89
What 3 steps does biosynthesis of polypeptide chain include?
Imitation, elongation and termination of translation
90
What is the sequence of protein biosynthesis?
Amino acid and ATP>amino acyl-AMP>AMP replaced with respective tRNA this forming aminoactyl tRNA
91
What is the main source of energy during translation process?
GTP
92
Where does the beta-oxidation pathway take place?
In the mitochondria
93
What are purine nucleotides synthesised on the base of?
5-phsphoribosyl-1-pyrophosphate
94
What is the main difference between purine and pyrimidine biosynthesis?
Pyrimidine nucleotides are first made in the cytosol and only the. Are attached to the sugar phosphate
95
What are the main source for biosynthesis of nucleotides?
Amino acids
96
What are pyrimidine nucleotides products of?
Aspartate and carbamyl-phosphate
97
What is purine attached to?
Phosphoribosyl pyrophosphate
98
What is purine nucleotide made using?
Nitrogen atoms form aspartic acid, glutamine and glycine. The remaining carbons obtained from formiate and CO2 and active form of folic acid is used to transport formiate
99
What does cycline-dependent kinase signalling regulate?
Cell cycle progression
100
What does pattern recognition receptor signalling do?
Induce innate immune response and bring antigens presenting cells to the site of injury
101
Where does beta-oxidation pathway take place?
In the mitochondria
102
In biosynthesis of fatty acids which associate with glycerol what do they form?
TAGs- triacylglycerol
