IMMS 1 Flashcards
What are two types of chromatin?
Euchromatin, Heterochromatin
Which type of chromatin is expressed?
Euchromatin (loose coils- easily expressed
- gene transcription occur)
Which type of chromatin is repressed?
Heterochromatin (tighter wound- hard expressed)
What is DNA wrapped round?
Histone proteins
What is function nucleolus?
rRNA synthesis- production ribosomes
What is function mitochondria?
Main site ATP synthesis
Function SER?
Mmebrane lipid synthesis, protein storage, phase 1 detoxification
Function RER?
Site protein synthesis
Lots ribosomes
What are 3 parts of golgi? Function
Cis- receives protein/lipid vesicles
Medial- modifies- adds sugars
Trans- releases- package into vesicle- exocytosed
Which cell is easy to see golgi?
Plasma cell- perinuclear hoff
Function lysosomes?
Protein degradation
How does lysosome achieve protein degradation?
pH5 maintained by H+/K+ ATPase
What are two types of vesicles?
Lysosomes
Peroxisomes
Function of peroxisime? (2)
Beta oxidation FA
Produces and destroys hydrogen peroxide
What makes up cytoskeleton? (3)
Microtubules
Intermediate filaments
Microfilaments
What is diameter of microtubules?
Motor protein?
Function microtubules? (2)
Diameter- 25nm (biggest)
Motor protein- tubulin
Function- mitosis, component cilia
What is diameter of intermediate filament?
Motor proteins?
Function intermediate filament? (2)
Diameter- 10nm (middle)
No motor proteins
Function- maintain cell integrity, cell to cell contact
What is diameter of microfilaments?
Motor proteins?
Function microfilaments? (2)
Diameter- 5-7nm (smallest)
Motor protein- myosin
Function- maintain cell integrity, motility
What is lipofuscin?
What colour?
Wear and tear pigment
Undergone oxidative lipid degradation
Brown
Where are lipids stored?
Adipocytes
Subcutaneous
Liver
What is glycoprotein?
Where is stored?
Glucose reserve
Stored in skeletal muscle and liver
Function of cell membrane? (5)
1) Semi-permeable- allow certain mol diffuse
2) Maintain structural integrity cell
3) Boundary- seperate intra and extracellular content
4) Contains receptors for self and foreign ID
5) Link adjacent cells
What are 2 membrane proteins?
Receptors
Channel
What are receptor proteins?
Outside binding- eg Ach
Triggers intracellular response
What are types of receptor proteins? (3) Most common?
1) Enzyme linked
2) Ion channel
3) G coupled- most common
What occurs in G coupled protein receptors?
Extracellular binding activated transduction pathway
Cascade internal reactions
What are diff types channel proteins? (3)
1) Ligand gated (depend ligand binding open)
Ligand chemical substance binds
2) Voltage gated- impulse transmission
3) Mechanical gated- open when stretched
What are 4 types of cell to cell junctions?
1) Tight junctions
2) Adherens
3) Desmosomes
4) Gap junctions
Function tight junctions? found?
No passage between cells
GI tract
BBB
Function adherens?
Bind adjacent actin bundles cells
Actin to actin
Function desmosomes?
Bind adjacent intermediate filaments
Intermediate filament to intermediate filament
Function gap junctions? What imp?
Allow adjacent passage ions and molecules
Key myocardium contraction at same time
Is diff/osmosis down or up gradient?
Down conc. gradient
What is facilitated diffusion?
Move down conc grad with protein
What 2 types active transport?
Primary- direct, Na+/KATPase
Secondary- cotransport, NaGlucose
Define exocytosis
Why does it occur?
Vesicles bud off CSM
Too big/hydrophobic for diffusion
Define endocytosis?
Intake of molecules in phagosome vacuole
What are 3 types of endocytosis?
What are they?
1) Phagocytosis- eating, engulf whole cells by neutrophil and macrophages
2) Pinocytosis- drinking, engulf dissolved solutes
3) Receptor mediated- engulf ligand-receptor complex
Definition of homeostasis?
Maintain constant internal conditions in normal range
What 3 modes of communication in homeostasis?
Autocrine
Paracrine
Endocrine
Where does autocrine act, where does it secrete?
Autocrine- act same cell
- secretion into ECF
Auto- self
Where does paracrine act, where does it secrete? E.g
Paracrine- act neighbouring cell
- secretion into ECF
- ACh
Where does endocrine act, where does secrete?
Endocrine- act distant cell
- secretion into blood
- ADH from posterior pit.
What is negative feedback? E.g
Any deviation away from normal then return to normal
Highly regulated
Maintaining body temperature
What is positive feedback? E.g
Amplification away from normal
Blood clotting
What are 3 types of hormones?
Peptide
Amino acid derivative
Steroid
What are peptide hormones made from?
Soluble in what?
Released into what?
What does it bind to?
Fast or slow acting?
What response does produce?
Is it premade and stored?
Made amino acids
Water soluble
Released directly blood
Binds to CSM
Fast acting- produce intracellular response
Premade and stored in vesicles (won’t suit fatty inside)
2 examples of peptide hormones?
ADH, insulin
What are steroid hormones made from?
Soluble in what?
Released into what?
What does it bind to/enter?
Fast or slow acting?
What response does produce?
Is it premade and stored?
Made cholesterol
Lipid soluble
Transported by protein in blood (albumin)
Diffuse through CSM
Slow acting
Not premade, not stored (suit fatty intracell)
Give two examples of steroid hormones?
Oestrogen, testosterone
What are AA derived hormones made from?
Soluble in what?
Released into what?
What does it bind to?
Fast or slow acting?
What response does produce?
Is it premade and stored?
(same peptide)
Made 1 amino acid
Water soluble
Released directly blood
Binds to CSM
Fast acting- produce intracellular response
Premade and stored in vesicles