BLOCK 1 Flashcards
Antibiotic vitamin deficiency
Vitamin K by eliminating of gut flora
Effect of NSAIDS
Reduce prostaglandin production which increases gastric acid secretion
Rate limiting enzyme in lipogenesis
Acetyl coA carboxylase
Type 1 collagen
Bone, skin and tendon
Type 2 collagen
Hyaline cartilage
Type 3 Cartilage
Reticular fibre- mutation of blood vessels Ehlers-Danlos syndrome
Type 4 collagen
Basal lamina, basement membrane- targeted in goodpasture syndrome
Type 5 collagen
Interstitial tissue- mutated in Ehlers-danlos syndrome
Which vitamin is important for forming collagen?
Vitamin C which hydroxylates proline and lysine in collagen- deficiency in collagen causes poor wound healing and capillary fragility for gum bleeding
What is the cause of Ehlers Danlos
Abnormality in type 1 and 3 collagen
When does centrosome duplication occur?
S phase
Which part of the cell cycle is the shortest?
Mitosis- specifically anaphase
Which part of interphase is the fastest?
G2 phase
Which part of the cell cycle is the longest?
G1 phase
What is the role of glucokinase?
Phosphorylates glucose to glucose-6 phosphoate
What are the energy stores in the body?
Glucose, protein, glycogen and fat as trialglycerol
What is a short term store of energy?
Glucose is the shortest and then glycogen that leasts less than a day
What is the longest store of energy?
Trialcglycerol
When is protein used as an energy store?
During starvation via gluconeogenesis
How does glycolysis occur?
Glucose activation from glucose -> glyceraldehyde-3 phosphate. This then will undergo substrate level phosphorylation to form pyruvate.
What are the rate limitating steps in glucose activation?
Hexokinase to form glucose-6 phosphate and phosphofructokinase to form fructose 1,6 bisphophate which are phosphorylation reactions that require ATP. In substrate level phosphorylation, the final stage via pyruvate kinase requires ATP.
What is the primary structure of a protein?
Sequence of amino acids in a polypeptide chain.
What is a secondary structure?
Folding of protein into alpha helices or beta-pleated sheets due to hydrogen bonds
What is a tertiary structure?
Shape of protein due to R group interactions of amino acids.
What is the protein quarternary structure?
Shape of protein due to poypetide chains
Cadherins
Cell adhesion molecules which form adheren junctions and homophilic interactions using Ca2+ to connect to cytoskeletin via beta catenin and alpha catenin internal segment.
Integrin
CAM with alpha and beta subunit that dissasociates when ligands bind to signal to intracellular domain
Selectin CAM
CAM with heterophilic interactions with carbohydrates on selectin proteins.
What are adheren junctions?
Structural junction that creates mechanical attachments via homodimer interactions with cadherens that support and anchor epithelia.
Desmomsomes
Localised patches of cell adhesion between desmodein and desmocollin adherin proteins which provide a link to cytoskeleton
Tight junctions
Formed of claudin and occludins that seal cells to regulate movement of substances in paracellular cleft
Gap junctions
Formed of connexin proteins that act as intracellular channels for movement of ions
Location of citric acid cycle
Mitochondrial matrix. Rate limiting step is isocitrate dehydrogenase
What is the rate limiting enzyme of glycogenesis?
Glycogen synthase
What is the rate limiting enzyme of glycogenolysis?
Glycogen phosphorlyase
Where is calcium mainly absorbed?
Small intestine
Which organelle transports organsims and other oganelles in the cell?
Microutbules- formed of alpha and beta-tubulin
Where are proteins translated?
Cytoplasmic ribosomes on RER
Role of smooth endoplasmic reticulum
Involved in protein folding before modification at golig apparatus. Synthesises steroids, lipids and phospholipids. Does not have ribsoomes so it is smooth. This organelle is in excess in the gonads and skin oil glands
Function of peroxisomes
Catabolism of long chain fatty acids
Location of lipid synthesis
SER
Microarray
Study gene expression of thousands of genes simultaneously
Missense mutation
Point mutation that causes different amino acid to be produced
Nonsense mutation
Mutation that codes for stop codon and shortens chain
What is the start codon?
AUG
WHat is the stop codon?
UAA
DNA of mitochondria
Double stranded circular DNA
N-linked glycoslylation
Attachment of carbodhydrate to nitrogen atom that occurs in RER
Ubiquitination
Occurs in proteasome
RNA splicing
removing introns to form mRNA in the nucleus
Fat soluble vitamin
Vitamin A, D, E, k
Why does the golgi add molecules to proteins?
For trafficking by lysosomes
Breakdown of large molecules
Lysosyme and proteasome
Quiscent stage
Stage zero where cells no longer divide
What stage of the cell cycle determines lengTH?
G1
Which enzyme unwides DNA strands for copying?
DNA helicase
Site of ribosome production?
Nucleolus
Importance of B1
Co factor for TCA cycle intermediates
Effect of competitive enzyme inhibitors on Vmax?
No effect
What is the most common type of collagen?
Type 1 collagen
Silent mutation
Single base mutation which does notchange amino acid
DNA microarray
Shows DNA structure by order of size using a fluroescent tag
How do ketone bodies form?
Occurs during starvation.acetoacetate, b-hydroxybutyrate and acetone. In the fed state, fatty acid oxidation occurs to convert fatty acids into acetyl coA and acyl coA
How are long chain fatty acids synthesised?
From acetylcoA
What is the function of the pentose phosphate pathway?
Generate ribulose-5-phosphate for producing amino acids and DNA. Generates NADPH (which is reduced NADP) which is important for fatty acid synthesise and steroid hormones and reduce oxidative stress.
Autocrine signalling
Acts on cell membrane of the same cell it’s released from such as growth factors
Intracrine signalling
Acts within cell such as steroid hormones
Direct signalling
Type of juxtacrine signallingMoves between cells through gap junctions. Present in the heart to allow electrical signals to be generated
Paracrine singalling
Uses diffusion to reach target cells
Juxtacrine
Acts on cells with physical contact. Includes gap junctions and notch transmebrnae receptor signalling that translocates to the nucleus.
Nodes of Ranvier
Voltage gated Na+ channels in between myelin
Lambert Eaton myasthenic syndrome
Antibodies block voltage gated Ca2+ channels opening and prevent release of acetylcholine for muslce contraction
What is the DNA storage molecule?
Chromatin
Which type of conditio will always be inherited or not affect males?
X linked- affected males won’t apss it onto son because otherwise son will be a copy of them since they need the Y to be identical
What DNA form is used in transcription?
Euchormatin which is unpacked
DNA synthesis
Requires folate. Dihydrofolate -> tetrahydrofolate via DHF reductase. Tetrahydrofolate donates methylgroup to dUMP -> dTMP. dTMP is a thymine/ a nucleotide monomer to form purine for DNA synthesis.
What is flurouracil?
Flurouracil (5-FU) is a topical cytotoxic drug to treat cancer. It is converted to F-DUMP which inhibits thymidylate synthase. Thymidylate synthase catalyses the conversion of dUMP -> dTMP (thymine) for thymine synthesis which inhibits gene expression. 5-FU can also be converted in-vivo to FUTP which replaces uracil in RNA to prevent RNA processing.
What is the short arm of a crhomosome?
P arm
What is the action of antibiotics?
Block tRNA which is used by prokaryotic enzymes for protein synthesis
What is the long arm of a chromosome?
Q arm
What is ATP turnover?
Our total body weight
What is an infinte energy store?
Adipose tissue
How can transcription factors rincrease gene expression?
Transcription facotrs can bind to enahncer gene region. Acetylation to histone protein, reducing DNA association for RNA polymerase to access DNA.
How can transcription factors reduce gene expression?
Bind to promoter gene to block RNA polymerase. They can cause deacetylation of histoe to strongly associate with DNA.
What is most polymorphic and used for identification?
Microsatellites like a dinucleotide being repeated. MHC is the most polymorphic
Genetic maps
Estimate of probability of recombination using linkage analysis
What is a single nucleotide variant?
Single nucleotide base difference
Hardy-Weinburg equilibrium
Predict genetic outcomes in non envolving population with random mating, large pop no migration, no mutation, no natural selection.
Majority of fluid in body?
IC fluid which is 2/3
What is the majroity of EC fluid?
Tissue fluid, then plasma fluid
Cause of oedema
Inflammation, lymphatic damage, low oncotic pressure due to low protein diet or kidney damage, high evenous pressure, due to tissue damage
What causes reabsorption?
Negative oncotic pressure due to plasma proteins
What causes filtration?
Hydrostatic pressure which is increased in oedema due to inflammation or high venous pressure in extreme
Specificity
specifity is the effect of a drug upon one individual pharmacological action.