IMMS Flashcards

1
Q

Mitochondria

A
o	double membrane
o	cristae
o	matrix (Kreb’s cycle)
o	inner membrane (oxidative phosphorylation
o	produces ATP
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2
Q

Endoplasmic reticulum

A

o rough – ribosomes for protein production

o smooth - lipid production

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3
Q

Golgi apparatus

A

o receives proteins and lipids from endoplasmic reticulum

o modifies and packages them into vesicles for transport

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4
Q

Vesicles

A

o lipid bilayer

o 3 types – lysosome, secretory and transport vesicles

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5
Q

Cytoskeleton

A
o	Function - keeps cell shape and organises parts of cell
o	Structure:
▪	Microtubules
▪	microfilaments (actin)
▪	intermediate filaments
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6
Q

Cell energy storage

A

o lipofuscin is droplet deposits around nucleus (increase with age)
o lipid droplets found mainly in adipose tissue
o glycogen is main cell storage of glucose

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7
Q

Cell membrane

A
o	phospholipid bilayer
o	interspersed with proteins, carbohydrates and cholesterol
o	function:
▪	protects the cell from outside,
▪	selectively permeable to ions
▪	transport in and out of cell
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8
Q

Transporter proteins

A

o Transmembrane
o move substances in and out of cell vie facilitated diffusion or active transport
● Desmosome:

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9
Q

Desmosomes

A

o specialised for cell to cell adhesion

o protein complexes found in the cell membrane of epithelial cells

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10
Q

Cell surface receptor

A

o bind to external ligand and convert extracellular information into intracellular information
o 3 types:
▪ ion channel - opens
▪ G protein - activates protein to open ion channel
▪ enzyme linked - receptor linked to intracellular enzyme

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11
Q

Endocytosis

A

(movement into cell)

  1. Molecules bind to receptors in clathrin-coated pit in cell membrane
  2. pits bud to form clathrin-coated vesicles
  3. vesicle fuses with intracellular endosome
  4. contents are either transported to lysosome or recycled into cell membrane
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12
Q

Exocytosis

A

out of cell

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13
Q

Diffusion

A

movement of a molecule from an area of high concentration to an area of low concentration (down conc gradient)

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14
Q

Facilitated diffusion

A

normal diffusion through a transmembrane protein – useful for large/polar molecules

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15
Q

Active transport

A

movement of molecules against concentration gradient – requires ATP

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16
Q

Homeostasis

A

the maintenance of stable internal conditions within the body

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17
Q

Cell communication

A

o autocrine - within same cell
o paracrine - signal affects nearby cells
o endocrine - signal secreted into blood

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18
Q

Feedback

A

o positive = amplification of process – chain reaction)

o negative = result of action inhibits another action

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19
Q

Water distribution within the body- 42kg

A

2/3 (28kg) Intracellular F
1/3 (14kg) ECF:
-3L= plasma
-11L= interstitial fluid

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20
Q

Osmoregulation

A
  1. low water levels detected by hypothalamic osmoreceptors
  2. Osmoreceptors sends signal to pituitary to release ADH
  3. ADH travels to kidney and causes increased fluid uptake
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21
Q

Fluid loss

A

o sensible can be measured - urine, faeces, breathing

o insensible cannot - evaporation from skin

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22
Q

Osmolality -

A

concentration of solutes in plasma PER KG OF SOLVENT

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23
Q

Osmolarity

A

concentration of solutes in plasma PER LITRE OF SOLUTION

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24
Q

Osmotic pressure

CHECK!!!!!

A

how easily solution can take in water vs oncotic pressure: specific type of osmotic pressure concerning albumin
is a form of osmotic pressure induced by proteins, notably albumin, in a blood vessel’s plasma (blood/liquid) that displaces water molecules, thus creating a relative water molecule deficit with water molecules moving back into the circulatory system within the lower pressure venous end of capillaries.

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25
Q

Oedema

A

increased movement of fluid from plasma to interstitial space, or decrease in vice versa

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26
Q

Types of oedema

A

o normal - increased hydrostatic pressure forces fluid out of vessels
o inflammatory - histamine increases blood vessel permeability
o lymphatic - lymph system doesn’t remove fluid from extracellular space
o hypoalbuminaemic - decreased albumin = decreased oncotic pressure

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27
Q

Carbohydrate

A

o made of monosaccharides - 6 carbon

o glycosidic bonds form between monosaccharaides to produce disaccharides/polysaccharides (condensation reaction)

28
Q

Lipid

A

o hydrophobic

o triglyceride - glycerol head with 3 fatty acid tails

29
Q

Nucleotide

A

o Structure:
▪ nitrogenous base
▪ pentose sugar
▪ phosphate group
o Phosphodiester bonds form between adjacent nucleotides
o Hydrogen bonds form between opposite nucleotides

30
Q

Amino acids

A
o	central carbon atom attached to:
▪	amine group
▪	carboxyl group
▪	hydrogen group
▪	variable group
o	Peptide bonds form between amino acids in condensation reaction
31
Q

Protein structure

A

o primary - specific sequence of amino acids
o secondary - alpha helix and beta pleated sheet
o tertiary - folding into 3D shape (disulphide bridges, H bonds and polar regions)
o quaternary - multiple tertiary proteins working together (haemoglobin)

32
Q

Enzyme

A

o biological catalyst
o protein and non-protein component
o induced fit theory
o coenzyme = non-protein component

33
Q

Intermolecular forces

Weak to strong

A

Van der Waals -> permanent dipole -> hydrogen bonds

34
Q

DNA and RNA:

A

pentose sugar (deoxyribose/ribose), phosphate group and nitrogenous base

35
Q

● Base pairings:

A

o cytosine to guanine
o adenine to thymine - replaced by uracil in RNA
o hydrogen bonds between base pairings

36
Q

● Semi-conservative replication

A

(1 original + 1 new DNA strand):

  1. Topoisomerase unwinds DNA from supercoiled state
  2. Helicase unzips DNA strand at replication fork
  3. DNA polymerase synthesises new DNA – leading strand produced continuously, lagging strand produced in short Okazaki fragments (assisted by DNA primase)
  4. New strands are joined up by ligase
37
Q

● Transcription and translation:

A
  1. RNA polymerase and transcription factors bind to promoter region on gene
  2. DNA strand unwinds and RNA polymerase moves across active gene, producing strand of mRNA
  3. Gene splicing – introns removed, exons reassembled in variable arrangement
  4. Mature mRNA travels from nucleus and the 5’ end binds to the ribosome
  5. tRNA with specific anticodon binds to corresponding codon on mRNA – amino acid is attached to tRNA
  6. Stop codons – UAA, UGA, UAG
38
Q

● Mis-sense:

A

single nucleotide polymorphism (SNP) = change in single nucleotide = potential change in amino acid

39
Q

● Non-sense:

A

SNP causes stop codon to be translated = not fully formed amino acid chain = non-functioning protein

40
Q

● Cell cycle:

A
  1. G1 phase – cellular contents are replicated
  2. S phase – chromosomes are replicated
  3. G2 phase – replication is checked for errors and components are assembled/arranged
  4. Mitosis – see below
41
Q

● Mitosis:

A
  1. Interphase:
    ▪ G1 -> S -> G2 phases (can’t see)
  2. Prophase:
    ▪ chromatin condenses to visible chromosomes
    ▪ centrioles migrate to poles of cell
  3. Prometaphase:
    ▪ nuclear membrane breaks down
    ▪ microtubules from centrioles bind to centromeres
  4. Metaphase:
    ▪ chromosomes line up in middle of cell (metaphase plate)
  5. Anaphase:
    ▪ Sister chromatids are pulled apart to opposite ends of cell by microtubules
  6. Telophase:
    ▪ Nuclear membrane reforms
    ▪ chromosomes decondense to form chromatin
  7. Cytokinesis:
    ▪ cytoplasm divides to form two daughter cells
42
Q

● Meiosis:

A
  1. Interphase – cell contents replicate (2n ->4n)
  2. Meiosis 1 – mitosis, but crossing over and independent assortment occurs (4n -> 2n)
  3. Meiosis 2 – daughter cells divide to form haploid cells (2n -> n)
43
Q

● Numerical abnormalities:

A

o during meiosis 1 or 2 chromosomes are not divided up equally
o Down’s Syndrome - genetic information missing???

44
Q

● Structural abnormalities:

A

o chromosomes/parts of chromosomes swap places during meiosis 1 and 2
o different sized chromosomes
o less serious than numerical because genetic information still present

45
Q

● Gametogenesis

A

– meiosis to form gametes

46
Q

● Mendel’s 2nd law

A

– the hereditary box crossover diagram (dominant and recessive alleles)

47
Q

● Gonadal mosaicism –

A

epigenetics means that environmental factors (mainly age) causes sperm/egg to have different genetic information to father/mother

48
Q

● Genotype -

● phenotype

A

the genetic makeup of an individual

– observable characteristics of an individual (genes and environment working together)

49
Q

● Inheritance:

A

o Mendelian - purely genes

o Multifactorial - combination of genes and environment

50
Q

● Autosomal dominant

A

= condition presents in heterozygous state – polycystic kidney disease, Huntington’s disease

51
Q

● Autosomal recessive

A

= condition only presents in homozygous state – cystic fibrosis, sickle cell anaemia

52
Q

● Sex linked inheritance (X linked inheritance):

A

o genes carried on maternal X chromosome
o transmitted through unaffected females and affects predominantly males
o haemophilia, muscular dystrophy
RECESSIVE + DOMINANT

53
Q

● Lyonisation:

A

o one of the maternal X chromosomes are inactivated
o in X linked inheritance, the X chromosome with the faulty gene could be active or inactive
o random process

54
Q

● Knudson’s two hit hypotheses –

A

cancer is a result of accumulated mutations to cell DNA, relates to discovery of cancer genes and carcinogenesis

55
Q

● Multifactorial diseases =

A

combination of genes and environment, risk of condition is higher in people with relatives with condition – schizophrenia, cancer, Alzheimer’s

56
Q

● Penetrance =

A

percentage of individuals with specific genotype that show expected phenotype

57
Q

● Variable expression

A

= individuals with same genotype may have differing phenotypes

58
Q

● Anticipation =

A

genetic defects affect successive generations early and more severely, due to repeat triplet sequences

59
Q

● Metabolism definition

A

– chemical processes occurring within the body to maintain life

60
Q

● Basal metabolic rate

A

– rate of energy use in the body for vital functions at rest

61
Q

● Factors affecting BMR:

A

o Age
o Gender
o Body size + composition

62
Q

● ATP – ADP cycle:

A

o ATP + water -> ADP + phosphate + H+ + heat energy
o Energetically favourable – negative Gibbs free energy
o Phosphate and H+ enter other metabolic pathways

63
Q

● Generation of ATP:

A

o Glycolysis
o Kreb’s cycle
o Oxidative phosphorylation

64
Q

● Glycolysis:

A
  1. Glucose -> glucose-6-phosphate
    ▪ Requires 1 ATP
    ▪ Catalysed by hexokinase
  2. Glucose-6-phosphate -> fructose-6-phosphate
  3. Fructose-6-phosphate -> fructose-1,6-bisphosphate
    ▪ Requires 1 ATP
    ▪ Catalysed by phosphofructokinase
    ▪ Inhibited by ATP, activated by AMP
  4. Fructose-1,6-bisphosphate -> glyceraldehyde-3-phosphate
  5. Glyceraldehyde-3-phosphate -> 1,3-bisphosphoglycerate
  6. 1,3-bisphosphoglycerate -> 3-phosphoglycerate
    ▪ Creates 2 ATP
  7. 3-phosphoglycerate -> 2-phosphoglycerate
  8. 2-phosphoglycerate -> phosphoenolpyruvate
  9. Phosphoenolpyruvate -> pyruvate
    ▪ Creates 2 ATP
65
Q

● Kreb cycle:

A
o	Takes place in mitochondrial matrix
o	Pyruvate -> acetyl CoA via pyruvate dehydrogenase
o	Oxaloacetate + acetyl coA -> citrate
▪	Catalysed by citrate synthase
o	Citrate -> isocitrate
▪	Catalysed by aconitase
o	Isocitrate -> Alpha-keto glutarate
▪	Catalysed by isocitrate dehydrogenase
▪	Releases NADH and CO2
o	Alpha-keto glutarate -> succinyl-coA
▪	Catalysed by alpha-ketoglutarate dehydrogenase
▪	Releases NADH and CO2
o	Succinyl coA -> succinate
▪	Catalysed by succinyl coA thiokinase
o	Succinate -> fumarate -> malate
▪	Catalysed by fumarase and malase
▪	Releases FADH
o	Malate -> oxaloacetate
▪	Catalysed by malate dehydrogenase
▪	Releases NADH
66
Q

● Glycolysis substrate mnemonic:

A
o	Good – glucose
o	Girls – glucose-6-phosphate
o	Fuck – fructose-6-phosphate
o	Fine – fructose-1,6-bisphosphate
o	Gentlemen – glyceraldehyde-3-phosphate
o	But – 1,3-bisphosphoglycerate
o	Prohibit – 3-phosphoglycerate
o	Penile – 2-phosphoglycerate
o	Pooper – phosphoenolpyruvateu
o	Penetration – pyruvate
67
Q

● Kreb’s cycle mnemonic:

A
o	Can – citrate
o	Adam – aconitate
o	Intrigue – isocitrate
o	A – alpha-keto glutarate
o	Super – succinyl coA
o	Sexy – succinate
o	Foxy – fumarate
o	Momma – malate 
o	Ok! - oxaloacetate