MTM WK2 - FUNDAMENTAL CELL PROCESSES

Question 1

CATABOLIC PATHWAY

Answer 1

breaks complex muscle to simple muscle (releases energy)

Question 2

ANABOLIC PATHWAY

Answer 2

builds complex muscle from simple muscle (uses ATP)

Question 3

GLYCOLYSIS YIELD

Answer 3

glucose = 2 pyruvate
2 NAD+ = 2NADH
2ADP = 2ATP

Question 4

GLYCOLYSIS PROCESS

Answer 4

glucose converted to fructose1-6-biphosphate (uses 2 ATP) which is split into glyceraldehyde-3-phosphate which is coverted to pyruvate by pyruvate

Question 5

ANAEROBIC RESP.

Answer 5

pyruvate converted to lactate by pyruvate dehydrogenase which reforms NAD+ from NADH (as NAD+ needed for glycolysis)

Question 6

CORI CYCLE (GLUCONEOGENESIS)

Answer 6

• lactate moved to liver & converted to glucose for respiration
• (2ATP to ADP) (NADH to NAD+) (GTP to GDP)

Question 7

PYRUVATE DECARBOXYLATION

Answer 7

pyruvate converted to acetyl-CoA & CO2 by pyruvate dehydrogenase (PDH) (NAD+ to NADH)

Question 8

PDH ENZYME REGULATION

Answer 8

• activated by calcium (CA2+ + H2O = Pi (activates enzyme)

- inactivated by NADH activating the kinase enzyme

Question 9

TCA YIELD

Answer 9

• acetyl CoA = CoA + 2CO2
• 3NAD+ = 3NADH (B3)
• FAD = FADH2 (B2)
• GDP + Pi = GTP
• after TCA, there are 10 NADH (each make 2.5 ATP) & 2 FADH2 (each make 1.5 ATP)

Question 10

ELECTRON TRANSFER CHAIN (ETC)

Answer 10

1. NADH (to compex1) & FADH (to complex 2) transfer high energy electrons to ETC
2. NADH oxidised to release 1 proton & 2 electrons (2 e- transport 4 protons)
3. electrons lose energy to each carrier (used to AT protons from matrix to intermembrane space)
4. way more H+ in intermembrane than matrix so pass down ATP synthase channel to form ATP (3 H+ = 1 ATP) (+ 1 more H+ to move ATP to cytosol)
5. electrons + protons added to O2 (terminal acceptor) to form H2O (cyanide can inhibit complex 4 to stop O2 accepting electrons)

Question 11

GLYCEROL PHOSPHATE SHUTTLE (GPS)

Answer 11

NADH made in glycolysis is in cytosol but can only be oxidised in mitochondria (BUT can’t cross membrane) so GPS uses it to form glycerol-3-phosphate which diffuses into mitochondria & forms FADH2)

Question 12

UNCOUPLED TRANSPORT IN BROWN ADIPOSE TISSUE

Answer 12

protons pass from intermembrane space to matrix alone (not through ATP synthase channels) through uncoupling proteins so no ATP forms (energy lost as heat (good to maintain body temp)

Question 13

WARBURG EFFECT IN CANCER

Answer 13

tumour cells undergo aerobic glycolysis which produces lots of metabolism which favours rapid proliferation of cell so there is rapid tumour growth (do glycolysis instead of oxidative phosphorylation even tho there is oxygen)

Question 14

MALATE/ASPARTASE SHUTTLE

Answer 14

1. malate dehydrogenase converts OAA to malate (to be transported into mitochondria) (NADH to NAD+)
2. malate reconverted back to OAA by malate dehydrogenase (NAD+ to NADH)
3. OAA can’t cross mitochondria so converted to aspartate which crosses back into cytosol & is reconverted back to OAA by mitochondrial malate dehydrogenase
   - MALATE ASPARTATE function is to get NADH into mitochondria (broken to NAD+ when making malate but reforms NADH in mitochondria later)

Question 15

BENEFITS OF BASAL SIDE OF EPITHELIAL CELL

Answer 15

• allows cell to receive nutrition from arterial supply

- enables cell to receive sensory supply

Question 16

TYPES OF EPITHELIAL TISSUE (layers)

Answer 16

SIMPLE (every cell rests on basal lamina (1 layer of cells))
STRATIFIED (cells arranged in layers on top of one another & only lowest layer is on basal lamina)
PSEUDOSTRATIFIED (single layer of irregularly shaped cells where all rest directly on basal lamina but cells are irregularly shaped so look like many layers not just one)

Question 17

LOOK AT ALBUM ON LOCATIONS OF DIFFERENT TYPES OF EPITHELIUM

Answer 17

SQUAMOUS - flat (central nucleus)
COLUMNAR - longer than it is wide (nucleus near base)
CUBOIDAL - cube shape (central nucleus)
TRANSITIONAL - can differentiate e.g. bladder stretching

Question 18

EPITHELIA WITH MICROVILLI

Answer 18

microvilli are in membrane and ACTUALLY BEND THE apical surface of MEMBRANE which increases SA for absorptive surface

Question 19

EPITHELIA WITH CILIA

Answer 19

anchor on top of apical surface of membrane to waft away fluids (sit right above goblet cells so waft away mucous made by goblet)

Question 20

KERATINISED EPITHELIUM

Answer 20

dead cells (cells at basal have nutrients but as you rise, less likely to live so the dead basal cells pushed up when new ones form which leaves a protective layer above epithelium)

Question 21

CELL JUNCTIONS

Answer 21

• TIGHT JUNCTIONS (found at apical region & stop molecules passing through intercellular space)
• ADHESIVE BELT (anchors adjacent cells)
• DESMOSOMES (main junction for binding cells together)(on sides)(hemidesmosomes at basal side to bind to connective)
• GAP JUNCTIONS (passageway between adjacent cells to let small molecules move between neighbouring cells)
• CARRIER MOLECULES BETWEEN ADJACENT CELLS

Question 22

METAPLASIA

Answer 22

reversible conversion of one differentiated cell type to another

Question 23

NEOPLASIA

Answer 23

abnormal & excess growth of tissue (cancer)

Question 24

DYSPLASIA

Answer 24

abnormal development of cells in tissue/organ (not cancer yet)

Question 25

HOW TO NAME EPITHELIUM

Answer 25

1. simple or compound 2. shape of upper layer 3. epithelium

Question 26

CELL CYCLE STAGES

Answer 26

1. G1 (growth & DNA rep.) 2. S (DNA rep.) 3. G2 (growth) 4. M (mitosis)

Question 27

G1 CHECKPOINT

Answer 27

ensures cell large enough to divide & enough nutrients for daughter cells (no go-ahead signal = cell enters non-dividing state (G0)

Question 28

G2 CHECKPOINT

Answer 28

ensures DNA rep. in S phase completed successfully (looks for damaged DNA)

Question 29

METAPHASE CHECKPOINT

Answer 29

ensures all chromosomes are attached to mitotic spindle

Question 30

KINASE PROTEIN

Answer 30

protein which activates/deactivates another protein by phosphorylating them

Question 31

CYCLIN-DEPENDENT KINASE (CdK)

Answer 31

- drive checkpoints | - stays in cell as inactive form until activated by cyclin

Question 32

PRODUCTION OF CYCLIN | also look at cyclin graph on phone

Answer 32

accumulates during different stages of cycle but by G2, there is enough cyclin available to form M-CdK (initiates mitosis but is switched off in process that destroys cyclin after mitosis)

Question 33

WAYS CELLS CAN BECOME ONCOGENIC

Answer 33

- receptor mutates so is always active = deregulated cell production - signalling G-protein mutates so is always active = deregulated cell production - regulatory proteins mutate so over expression of transcriptional factor

Question 34

P53 GENE

Answer 34

- regulates G1/S phase | - DNA damage = higher level of P53 = activates transcription of CdK inhibitor

Question 35

CONSEQUENCES OF CHECKPOINT FAILURE

Answer 35

- cells produced even in absence of growth factor - replication of damaged DNA - division of cells with wrong number of chromosomes

Question 36

GROWTH FACTOR

Answer 36

- stimulates cell division - they target receptors to activate G1-CdK which phosphorylates pRB so releases TF regulators (activate genes for cell cycle)

Question 37

GF SIGNALLING PATHWAY

Answer 37

receptor = RAS protein (g-protein) = kinase cascade (kinase 1 activates kinase 2 etc) = gene regulatory protein form = response

Question 38

RESTRICTION POINT

Answer 38

- regulated by retinoblastoma protein (tumour-suppressor which is activated by CdK which phosphorylate retinoblastoma protein when GF present & retinoblastoma detaches from transcription regulators so transcription occurs (no GF = retinoblastoma attaches to transcriptin regulators so no mitosis happens) - point in G1 checks if GF present before starting mitosis

Question 39

4 stages where ATP made in glycolysis

Answer 39

1. glucose -> gluocse-6-phosphate (hexokinase) 2. fructose 1,6 biphosphate -> fructose-6-phosphate (phosphofructokinase) 3. 1,3-biphosphoglycerate -> 3-phosphoglycerate (phosphoglycerate kinase) 4. phosphoenolpyruvate -> pyruvate (pyruvate kinase)