Epithelial Cells And Tca Cycle

Front 1

Zona Adherens

Back 1

Also called belt desmosomes, attached through cadherins (Calcium dependent). Bind epithelial cells together. Go completely around the cell

Front 2

Junctional Complex

Back 2

Entire area in which two cells are attached to one another. Most apical point is the occluding junction. At the level of the light microscope constitutes terminal bars.

Front 3

Sequence of Junctions in the lateral edges of enterocytes

Back 3

Occluding Junctions - (most apical) Zona Occludens, Anchoring junctions - Zona Adherens (belt desmosomes), spot desmosomes (spot weld)

Front 4

Occluding Junctions

Back 4

Also known as tight junctions, function to prevent the leakage of material in the lumen along the lateral surface of the cells. Form a permeability barrier between the cells and prevent migration of proteins in the lateral plasma membranes to the apical surface. The plasma membranes of the two cells appear to fuse. Zonula occludens in columnar epithelial cells.

Front 5

Belt (Band) Desmosomes

Back 5

More basally located from occluding, function as anchoring junctions, in columnar cells called zonula adherens. Serve as anchoring sites for actin microfilaments.

Front 6

Terminal web

Back 6

A network of filaments in the apical cytoplasm of cells. Consists of actin filaments and myosin and spectrin II.

Front 7

Spot desmosomes

Back 7

Anchor two cells together (not restricted to epithelial cells) Called macula adherens. Composed of cytokeratin intermediate filaments anchored to the plasma membranes and extend into the cytoplasm. Contain desmoplankins which are attached to the intermediate filaments. Therefore is an anchoring site for intermediate filaments.

Front 8

Hemidesmosomes

Back 8

Attach the basal surface of the epithelial cells to the extracellular matrix. Resemble half desmosomes. Have intermediate filaments to plasma membrane but bound by integrin to glycoproteins in the extracellularmatrix.

Front 9

Brush Border

Back 9

In intestinal epithelial cells and proximal tubules of Kidney. Tightly packed, ordered arrangements of microvilli. Contain a core of actin filaments that enter the cytoplasm through the terminal web.

Front 10

Cilia

Back 10

Longer than microvilli. Move mucus in respiratory tract. 9 outer triplets of microtubules w/ 2 in basal bodies which stabilize the ciliary structure and act as microtubule organizing centers. The axoneme (top) of the cilia consists of 9 outer doublets and 2 inner microtubules. Dynein moves retrograte (-) and causes the cilia to move.

Front 11

Exocrine glands

Back 11

Secrete products into a system of channels or ducts

Front 12

Endocrine glands

Back 12

Secrete products into underlying connective tissue which then make their way to the blood.

Front 13

Acini

Back 13

Grape like clusters of cells that are secretory units. Cells that constitute them are pyramidal, rounded and have a basally located nucleus.

Front 14

Mixed gland

Back 14

Contains both serous and mucous acini. Serous will stain darkly, mucous will be lighter.

Front 15

Mucous gland

Back 15

Only mucous, more viscous protein product which copmresses the nuclei of the acinar cells to the base. Cytoplasm filled with mucus droplets.

Front 16

Serous gland

Back 16

Oily protein product.

Front 17

Goblet cells

Back 17

Mucous, unicellular, exocrine mode of excretion

Front 18

Connexon

Back 18

An individual gap junction

Front 19

6 Characteristics of Epithelium

Back 19

Polar, Have Junctions, Avascular, Basement Membrane, Free surface, Highly cellular

Front 20

Artery in microscope

Back 20

possess round lumen with thick mucular wall. Has internal elastic lumen (stitch pattern)

Front 21

3 stages of skin

Back 21

Epidermis (outer) - Dermis - hypodermis

Front 22

Glands are classified by: (4 things)

Back 22

Mode and Type of secretion, Shape, Presence/Absence of Ducts

Front 23

Sebacious gland

Back 23

Hair follical associated sweat gland that is multicellular, has a simple duct, Aveolar, holocrine secretion

Front 24

Eccrine gland

Back 24

Sweat gland. Has a simple coiled tubular duct, small lumen, merocrine serous secretions

Front 25

Apocrine gland

Back 25

Sweat gland. Has a large lumen, simple coiled tubular duct, merocrine mode of secretion, serous secretion,

Front 26

Distinguishing Stratified Squamous from transitional

Back 26

Stratified Squamous - Elongated, densly staned nuclei with heterochromatin
Transitional- Round nuclei with some euchromatin

Front 27

Equation for the overall reaction carried out by the TCA cycle

Back 27

CH3COOH + 2 H2O -> 2CO2 + 4x2H2

Front 28

Total number of ATPs that can be generated from one turn of the cycle

Back 28

10

Front 29

The comitted step of the TCA Cycle

Back 29

Isocitrate to alpha-ketoglutarate via Isocitrate dehydrogenase

Front 30

Describe the similarities between the oxidative decarboxylations of pyruvate -> succinyl CoA and alpha-ketoglutarate -> succinyl CoA. Also name the 5 enzymes involved.

Back 30

1) Pyr + NAD + CoASH -> NADH + CO2+ AcCOA

2)alphaKG + NAD + CoASH -> sucCoA+ NADH + CO2

TPP, LIP, FAD, CoA, NAD

Front 31

What is anapleroisis? Which intermediate in the TCA cycle can undergo this?

Back 31

Oxaloacetate is replenished from pyruvate or can be formed from aspartate via transamination

Front 32

How can alpha-ketoglutarate be regenerated?

Back 32

Glutamate -> alpha ketoglutarate via trans amination

Front 33

Which intermediates in TCA can serve as precursors for the synthesis of (a) glutamic acid, (b) apartic acid, (c) acetyl CoA, and fatty acids, (d) heme

Back 33

a) alpha-KG
b) OxaloAc
c) Citric acid
d) Succinyl CoA

Front 34

What role does oxaloacetate play in the the TCA cycle? Name the enzyme involved in the synthesis of oxaloacetate from pyruvate

Back 34

OxAc is a catalyst. Synthesized by action of pyruvate carboylase.

Front 35

Steps where TCA cycle is regulated.

Back 35

1) the rate of formation of AcCoA from Pyruvate is controlled by elevated Ca++ and reduced ATP, NADH, AcCoA

2) Isocitrate dehydrogenase requires ADP as a positive stimulatory modulator

3) Isocitrate to alphaketoglutarate regulated by ATP and NADH

alphaKG to Succinyl CoA regulated by ATP, NADH and Succinyl CoA

Front 36

Role Biotin plays in the TCA cycle.

Back 36

Biotin used in raction of pyruvate carboylase to form AcCoA and then which forms OxAc and ADP

Pyr + CO2 + ATP + H2O -> OxAc + ADP + Pi + 2H+

Front 37

How does pyruvate transverse the inner mitochondrial membrate?

Back 37

Via a symporter along with a proton

Front 38

State the type of raction in which thiamine (Vit B1) participates as a Co-enzyme.

Back 38

Oxidative decarboxylation such as pyruvate to AcCoA and alpha-KG to SuccCoA

Front 39

What diseases result from a deficiency of thaimine?

Back 39

Beri Beri, Werner-Korsacoffs

Front 40

Describe a diagnostic test for thiamine deficiency.

Back 40

Transketolase utilises it as a substrate

Front 41

Key functional groups of lipoic acid

Back 41

Disulfide group- actas as a carrier for hydrogen and acetyl groups

Front 42

Covalent interaction between lipoic acid and the enzyme dihydrolipoyl transacetylase (E2)

Back 42

Forms an amide bond linkage

Front 43

Name Vitamins that are essential for the the biosynthesis of NAD+, FAD, FMN, and CoA

Back 43

Niacin for NAD, FAD and FMN need Riboflavin (B2), CoA requires Pantothenic acid (a B vitamin)

Front 44

Name the enzymes involved in the TCA Cyle in order of action.

Back 44

Pyruvate Dehydrogenase, Citrate Synthase, Aconitase, Aconitase, Isocitrate Dehydrogenase, Alpha Ketoglutarate Dehydrogenase, Succinyl CoA synthetase, Succinate Dehydrogenase, Fumarase, Malate Dehydrogenase