IMMS Flashcards
what does the mitochondria consist of
double membrane cristae matrix (Krebs cycle) inner membrane (oxidative phosphorylation) - produces ATP
what does rough ER have
ribosomes for protein production
what does rough ER do
protein production
what does smooth ER do
produce lipids
what does Golgi apparatus do
- receives proteins n lipids from ER
- modifies and packages them into vesicles for transport
what do the cis, medial and trans Golgi faces do
cis - nearest to nucleus, protein phosphorylation
medial - forms oligosaccharides (by adding sugar to protein n lipids)
trans - packages into vesicles n proteolysis
what do vesicles form
lipid bilayer
what does the cis golgi face do
nearest to nucleus, protein phosphorylation
what does the medial golgi face do
forms oligosaccharides (by adding sugar to protein n lipids)
what does the trans Golgi face do
packages into vesicles n proteolysis
what are the 3 types of vesicles
- lysosome
- secretory
- transport
what does the cytoskeleton of the cell do
keeps cell shape and organises parts of cell
what is the structure of the cytoskeleton (smallest to largest)
microfilaments (actin) 5nm
intermediate filaments 10nm
microtubules 25nm
which cytoskeletal structure is 5nm
microfilaments
which cytoskeletal structure is 10nm
intermediate filaments
which cytoskeletal structure is 25nm
microtubules
what are the 3 types of cell energy storage
- lipofuscin
- lipid droplets (in adipose tissue)
- glycogen
what is glycogen
main cell storage of glucose
where are lipid droplets mainly found
adipose tissue
what is lipofuscin
droplet deposits around nucleus
how does lipofuscin alter with age
increases
what does the cell membrane consist of
phospholipid bilayer
interspersed with proteins, carbs and cholesterol
what is the function of the cell membrane (3)
- protects cell from outside
- selectively permeable to ions
- transport in and out of cell
how do transporter proteins act
transmembrane
- move substances in n out of cell (facilitated diffusion or active transport)
what are desmosomes specialised for
cell to cell adhesion
what are desmosomes
protein complexes found in cell membrane of epithelial cells
what do cell surface receptors do
bind to external ligand convert extracellular info into intracellular info
what are 3 types of cell surface receptors
- ion channels (opens)
- G protein (activates protein to open ion channel)
- enzyme linked (receptor linked to intracellular enzyme
what is receptor mediated endocytosis
pinocytosis
what are the 4 steps of endocytosis
- molecules bind to receptors in clathrin-coated pit in cell membrane
- pits bud to form clathrin-coated vesicles
- vesicles fuse with intracellular endosome
- contents are either transported to lysosome or recycled into cell membrane
define diffusion
movement of a molecule from an area of high conc to an area of low conc down conc grad
define facilitated difffusion
normal diffusion through a transmembrane protein
what is facilitated diffusion useful for
large or polar molecules
define active transport
movement of molecules against conc gradient (uses ATP)
define homeostasis
maintenance of stable internal conditions within the body
what are the 3 types of cell communication
autocrine (Within same cell)
paracrine (Signal effects nearby cells)
endocrine (signal secreted into blood)
what is autocrine cell communication
within the same cell
what is paracrine cell communication
signal affects nearby cells
what is endocrine cell cmmunication
signal secreted into blood
what is positive feedback
amplification of process - chainreaction
what is negative feedback
result of the action inhibits another action
****what does extracellular fluid consist of
80% extracellular space
20% plasma
what are the 3 steps to osmoregulation (dehydration)
- low water levels detected by hypothalamic osmoreceptors
- osoreceptors send signal to pituitary to release ADH
- ADH travels to kidney and causes increased fluid uptake
what is the difference between sensible and insensible fluid loss
sensible can be measured: urien, faeces, breathing
insensible cannot be measured - evaporation
list examples of sensible fluid loss
urine
faeces
breathing
(measured)
name an example of insensible fluid loss
evaporation
cat be measured
what is diff btwn osmolality and osmolarity
conc of solutes in plasma per KG (osmolality) or per LITRE (osmolarity) of solution
define osmolality
conc of solutes in plasma per kg of solution
define osmolarity
conc of solutes in plasma per litre of solution
define osmotic pressure
hoe esily solution can take in water
define oncotic pressure
type of osmotic pressure concerning alubmin; pressure exerted
define oedema
increased movement of fluid from plasma to interstitial place, or decrease (vice versa)
name 4 types of oedema
normal
inflammatory
lymphatic
hypoalbuminaemic
what is normal oedema
increased hydrostatic pressure forces fluid out of vessels
what is inflammatory oedema
histamine increases blood vessel permeability
what is lymphatic oedema
lymph system doesn’t remove fluid from extracellular space
what is hypoalbuminaemic anaemia
decreased albumin therefore decreased oncotic pressure
what are carbs made of
monosaccharides - 6 carbon
which bonds form btwn monosaccharides to produce di/polysaccharides (and what type of reaction is this)
glycosidic
condensation
are lipids hydrophilic or phobic
phobic
what is a triglyceride
glycerol head with 3 fatty acid tails
what does a nucleotide consist of (3)
nitrogenous base
pentose sugar
phosphate group
which bond forms btwn adjacent nucleotides
phosphodiester
which bonds form opposite nucleotides
hydrogen
in an amino acid, what is the central carbon atom attached to (4)
amine goup
carboxyl group
hydrogen group
variable group
which bonds form btwn amino acids in a condensation reaction
peptide bonds
what is primary protein structuer
specific sequence of amino acids
what is secondary protein structure
alpha helix n beta pleated sheet
what is tertiary protein structure
folding into 3d shape eg disulphide bridges, h bonds and polar regions
what is quaternary protein structure
multiple tertiary proteins working together eg Hb
discuss enzymes
- bilogical catalyst
- protein and non-protein component
- induced fit theory
- coenzyme: non protein component
what are the intermolecular forces (weakto strong)
vDW - permanent dipole - hydrogen bonds
what kind of sugar are DNAand RNA
pentose
what do DNA and RNAconsist of
pentose sugar
phosphat group
nitrogenous base
what bonds are btwn base pairings
hydrogen
what are the 4 steps of semi conservative replication (1 original and 1 new DNA strand)
- topoisomerase unwinds DNA from supercoiled state
- helicase unzips DNA strand at replication fork
- DNA polymerase synthesises new DNA - leading strand produced continuous, lagging strand produced in short Okazaki fragments (asissted by DNA primase)
- new strands joined up by ligase
what does topoisomerase do in semi conservative replication
unwinds dan from supercoiled state
what does helices do
unzips dna strand at replication fork
what does DNA polymerase do
synthesises new dna
what are the 5 steps of transcription and translation
- RNA polymerase and transcription factors bind to promoter region on gene
- DNA strand unwinds and RNA polymerase moves across active gene, producing strand of mRNA
- gene splicing - introns are removed, exons reassembled in variable rearrangement
- mature mRNA travels form nucleus and the 5’ end binds to ribosome
- tRNA with specific anticodon binds to corresponding mRNA codon - amino acid attached to tRNA
name 3 stop codons
UAA
UGA
UAG
define mis-sense
SNP (single nucleotide polymorphism)
- change in single nucleotide may result in potential change in amino acid
define non-sense
SNP causes stop codon to be translated so not fully formed amino acid chain = non functioning protein
what are the 4 steps in the cell cycle
- G1 phase - cellular contents replicated
- S phase - chromosomes replicated
- G2 phase - replication checked for errors, components reassembled and rearranged
- MITOSIS
what happens during g1
cellular contents replicated
what happens during s phase
chromosomes replicated
what happens during g2 phase
replication checked for errors, components reassembled n rearranged
what is interphase
g1 - s - g2 (can’t see
what happens in prophase
- chromatin condenses to visible chromosomes
- centrioles migrate to poles of cell
what happens in prometaphase
- nuclear membrane breaks down
- microtubules from centrioles bind to centreoeres
what happens in metaphase
- chromosomes line up in middle of cell (metaphase plate)
what happens in anaphase
sister chromatids pulled apart to opposite ends of cell by microtubules
what happens during telophase
- nuclear membrane reforms
- chromosomes decondense to form chromatin
what happens during cytokinesis
cytoplasm dives to form 2 daughter cells
what are the 3 steps of meiosis
- interphase (contents replicate, 2n - 4n)
- meiosis 1 - mitosis, but crossing over n independent assortment occurs (4n - 2n)
- meiosis 2 - daughter cells divide to form haploid cells (2n - n)
what happens during meiosis 1
mitosis, but crossing over n independent assortment occurs (4n - 2n)
what happens during meiosis 2
daughter cells divide to form haploid cells (2n - n)
what is Down syndrome
trisomy 21 - numerical abnormality
are structural abnormalities more or less serious than numerical
less bc genetic info still present just diff sizes
what is gametogenesis
meiosis to form gametes
what is Mendel’s 2nd law
hereditary box crossover diagram (dominant n recessive alleles)
what is gonadal mosaicism
epigenetic means env factors (eg age) causes sperm n egg to have diff genetic info to mum n dad
define genotype
genetic makeup of individual
define phenotype
observable characteristsitcs of an individual
name 2 types of inheritance
mendelian
multifactorial
what is mendelian inheritance
purely genes
what is multifactorial inheritance
comb of genes n env
what is autosomal dominance
condition presents in heterozygous state
what is an example of autosomal dominant
huntingtons disease
what is autosomal recessive
condition only presents in homozygous state
name 2 examples of autosomal recessive
CF
sickle cell anaemia
what is sex linked inheritance (x linked)
genes carried on maternal x chromosome
- transmitted through unaffected females, affects mostly males
what are 2 examples of x linked inheritance
haemophilia
muscular dystrophy
which inheritance affects mostly males
x linked
what is lyonisation
1 materanal x chromosome is inactivated, random (in x linked: faulty x could be active or inactive)
what is knudson’s 2 hit hypothesis
cancer is a result of accumulated mutations to cell DNA
what is multifactorial disease
comb of genes n env eg schizophrenia
risk of cond higher in relatives
what is penetrance
percentage of individuals w specific genotype that show expected phenotype
what is variable expression
individuals w same genotype may have differeing phenotypes
what is anticipation
genetic defects affect successive generations early and more severely, due to repeat triplet sequences
what is the definition of metabolism
chemical processes occurring within body to maintain life
define basal metabolic rate
rate of energy use in body for vital functions at rest
which factors affect bmr
age
gender
body size n composition
is the ATP-ADP cycle energetically feasible
favourable - negative gibs energy
what are 3 methods of ATP genertion
glycolysis
krebs cycle
oxidative phosphorylation
