week 1

Question 1

ABC Transporters and example

Answer 1

ATP Binding Cassett
Active transport–needs ATP

EX: CFTR (cystic fibrosis conductance regulator)- acts as a chloride ion channel. Flows down [] gradient, does not pump.

Question 2

ω-6 fatty acids (essential)

Answer 2

Linoleic acid (18:2)– PUFA (polyunsaturated fatty acid)

Arachidonic acid

Question 3

ω-3 fatty acids (essential)

Answer 3

α-linoleic acid (18:3)– PUFA (polyunsaturated fatty acid)

EPA and DHA

Question 4

Homeostasis

Answer 4

Maintenance of a stable internal environment despite external variances.

Question 5

Positive feedback and examples

Answer 5

Amplify the original disturbance. Has a definitive endpoint.

Ex: birth, ejaculation, ovulation.

Question 6

Negative feedback and example

Answer 6

Action taken to prevent further change.

Ex: blood glucose level. Blood glucose too high, beta-cells sense, secrete insulin, glucose re-uptake.

Question 7

Steady state

Answer 7

Maintenance of a state that does not change with time, requires Energy.

Ex: ECF[Na+]>ICF[Na+]

Question 8

Equilibrium

Answer 8

No net energy is transfered between two compartments.

Both compartments have same amount of free energy.

Question 9

Nucleus

Answer 9

DNA is sequestered in the nucleus.

Question 10

Ribosomes and 2 types

Answer 10

Made in the nucleolus and enters cytoplasm.

Site of protein synthesis (translation)

1. Membrane-bound ribosomes
2. Free ribosomes

Question 11

Membrane-bound ribosome

Answer 11

Attached to RER

Produce:
lysosomal proteins
secreted proteins
plasma membrane proteins

Ribosome->ER->Golgi-> lysosome, secretion, plasma membrane

Question 12

Free ribosomes

Answer 12

Unattached to membrane.

Nucleus
Mitochondria
Cytosol
Peroxisomes

Question 13

Rough ER (RER)

Answer 13

Protein synthesis for plasma membrane, lysosome, or secretion.

Question 14

Smooth ER (SER)

Answer 14

Lipid metabolism, detoxification (liver), sequester calcium (muscle)

Question 15

Golgi apparatus

Answer 15

Complex of flatten, membrane-enclosed cisternae.

1. Post-translational modifications
2. Sorting
3. Packaging

Question 16

rER & Golgi Transport

Answer 16

COP-I coated vesicles: Retrograde. CGN to rER.

COP-II coated vesicle: Anterograde.
rER to CGN.

Question 17

Lysosome

Answer 17

Digestive organelle. Intracellular digestion of macromolecules.

Question 18

Mannose 6-Phosphate (M6P)

Answer 18

M6P receptor in TGN recognize lysosomal enzyme and transport to lysosomes.

Question 19

Lysosomal storage disease (LSD)

Answer 19

Caused by mutation from mutations in genes that encode lysosomal enzymes. Accumulation of undigested products. Cell death.

*Impacts neurons and CNS.

Ex: Tay-Sachs Disease
Deficiency of HEXA (beta-hexosaminidase A, alpha-subunit)
Accumulation of GM2 ganglioside

Question 20

Mitochondria

Answer 20

Generate ATP.
Double stranded circular DNA.

Inner membrane=oxidative reactions, synthesize ATP, regulate metabolite transport.

Intermembrane space= cytochrome c (programmed cell death)

Outer membrane= porins

Question 21

Mitochondrial diseases

Answer 21

Affects tissues that require large amounts of ATP.

Leber hereditary optic neuropathy
Myoclonic epilepsy with ragged red fibers (MERRF)

Question 22

Peroxisomes and diseases

Answer 22

Degrade toxic reactive oxygen molecules

Important for fat metabolism.
Synthesized by free cytoplasmic ribosomes.

Ex: Zellweger Syndome

Question 23

Nucleolus

Answer 23

Site of ribosome production.

RNA transcription and ribosomal subunit assembly.

Question 24

Nuclear envelope

Answer 24

Inner nuclear membrane- stabilizes the nuclear envelope.

Outer nuclear membrane- continuous with the rER. Cytoplasmic surface has ribosomes.

Question 25

Nuclear pore complex (NPC)

Answer 25

For transport between nucleus and cytoplasm. Spans inner and outer membrane.

Question 26

Chromatin structure (2 types)

Answer 26

Chromosomes in various degree of uncoiling. Euchromatin- lightly stain. Less condensed. More transcriptionally active! Heterochromatin-densely stain. More condensed. Less transcriptionally active.

Question 27

Lysosomal degradation (3 types)

Answer 27

1. Phagocytosis 2. Endocytosis 3. Autophagy (Self eating. Turnover of organelles for new ones)

Question 28

Intracellular inclusions

Answer 28

Cytoplasmic or nuclear structures formed from metabolic products of the cell. Pigments - Lipofuscin - Hemosiderrin - Melanin Glycogen (store glucose) Lipid (energy store and source of short carbon chains for membrane synthesis)

Question 29

Cytoskeleton protein filaments

Answer 29

1. Actin filaments 2. Microtubules 3. Intermediate filaments Acts as tracks for motor proteins to move material within the cell.

Question 30

Actin filaments

Answer 30

Anchorage | Structural core of microvilli and stereocillia

Question 31

Intermediate filament

Answer 31

Resist sheer force ``` Keratins Vimentin Neurofilaments Lamins Beeded filaments ```

Question 32

Microtubules

Answer 32

Cilia Flagella Centrioles Centrosome

Question 33

Centrosome

Answer 33

Organizes microtubules. Initiates microtubule formation. Contains a pair of centrioles.

Question 34

Cilia

Answer 34

Microtubule-based, hair like strucutre. 9+2 arrangement Pair of dynein arms Anchored to cell via basal body.

Question 35

Primary cilia

Answer 35

``` Sensory antennae -photoreceptors -chemoreceptors -mechanoreceptors 9+0 arrangement ```

Question 36

Microtubule motors

Answer 36

Dynein-- moves toward (-) ie cilia and flagella Kinesin-- moves toward (+)

Question 37

Cell movement

Answer 37

Protrusion-driven by actin polymerization Attachment Contraction *Actin motor

Question 38

Membrane protrusion structures (3)

Answer 38

Filopodia (finger like projections) Lamellipodia (sheet-like) Pseudopodia (3D projection)

Question 39

Neutrophil migration

Answer 39

Extravasation 1. rolling 2. activation 3. adhesion 4. transendothelial migration Chemotaxis

Question 40

Membrane lipid (3)

Answer 40

Cholesterol-decreases fluidity. Intercalates between phospholipids. Glycolipid-outer monolayer. contain sugar. Phospholipid-most abundant

Question 41

Phospholipids (5)

Answer 41

``` Phosphatidylserine Phosphatidylethanolamine Phosphatidylcholine Phosphatidylinositol Sphingomyelin ```

Question 42

2 major classes of membrane protein

Answer 42

Lipids | Proteins-integral and pheripheral

Question 43

Integral membrane proteins (6)

Answer 43

1. Pumps/carrier/transporters 2. Receptors 3. Linkers 4. Channels 5. Enzymes 6. Structural proteins

Question 44

Glycocalyx

Answer 44

Carbohydrate rich zone at cell surface. Cell-cell recognition Lectins Protection Microenvironment of cell surface

Question 45

Vesicular trafficking (3)

Answer 45

1. Constitutive secretory pathway 2. regulated secretory pathway 3. lysosomal pathway

Question 46

Endocytosis (3)

Answer 46

Receptor mediated (cargo specific, clathrin dependent) pinocytosis (non specific, clathrin independent) phagocytosis (clathrin independent, actin dependent)

Question 47

Exocytosis (2)

Answer 47

Regulated (secretory cells ie endocrine, exocrine, neurons)- may be stored until needed Constitutive (substance continuously delivered to plasma membrane)