Physiology Cell And Cell Structure

Front 1

What are the properties of eukaryotic cells?

Back 1

size, ability to form multicellular systems, give rise to diverse forms of life to exploit diverse ranges in environment,

Front 2

Increase in size and multicellularity causes problems in SA to volume ratio. What ensures heat can still be dissapated?

Back 2

Organelles of cell

Front 3

Why do cells require compartmentalization?

Back 3

Metabolic complexity and large size requires compartmentalization

Front 4

What are 5 advantages of compartmentalization?

Back 4

Enzymes concentrated in one location, substrates can accumulate in specific compartments, pH, ions/cofactors, allosteric regulation

Front 5

What is rate of enzyme-catalyzed reaction dependent on?

Back 5

Enzyme activity and amount of substrate

Front 6

At what pH do pepsin and lysosomes function best at?

Back 6

Low pH

Front 7

At what pH does amylase function best at?

Back 7

7.4

Front 8

What happens when a substrate binds to an allosteric site on an enzyme?

Back 8

Active site changes shape

Front 9

Which part of the phospholipid bilayer is polar?

Back 9

Heads

Front 10

Which part of the phospholipid bilayer is non-polar?

Back 10

Tails

Front 11

What is cholestrol embedded in?

Back 11

Phospholipid bilayer

Front 12

Glycolipids are ONLY found where?

Back 12

Extracellular surface

Front 13

Where are globular proteins found?

Back 13

Embedded in phospholipid bilayer

Front 14

What contributes to the asymmetry of membrane?

Back 14

Glycolipids

Front 15

What the particulate membrane model?

Back 15

Single layer of globular subunits of lipids and proteins

Front 16

What is the lamellar membrane model?

Back 16

Lamination of SHEET-like layers of proteins and lipids (double layer of lipids between 2 layers of protein)

Front 17

What 4 factors affect fluidity?

Back 17

1.cholestrol content
2.hydration
3.fatty acid side chain
4.temperature

Front 18

What is a phospholipid composed of?

Back 18

Phosphotidyl group complexed to structures such as choline, serine (etc.)

Front 19

What is the most common lipid present in membranes?

Back 19

Phospholipids

Front 20

How do fatty acid chains respond to changes in diet?

Back 20

Change in length and degree of saturation

Front 21

Where does beta oxidation occur?

Back 21

Mitochondria

Front 22

What is a triglyceride composed of?

Back 22

Glycerol and 3 fatty acids

Front 23

Cholestrol has both charged and non-charged parts. True or false?

Back 23

True

Front 24

List 4 reasons why cholestrol is important in membranes.

Back 24

Allows fatty acid chains to be more tightly bound which reduces permeability, bilayer becomes thicker preventing crystallization, provides mechanical stability, enhances fluidity

Front 25

What percentage of extracellular lipid moiety is composed of glycolipids?

Back 25

5%

Front 26

What is a possible function of oligosaccharides?

Back 26

May function in intercelllular communication, can be highly complex

Front 27

What are most glycolipids derived from?

Back 27

Sphingosine

Front 28

What are neutral glycolipids?

Back 28

Glycolipids composed of polar head with anywhere from 1-15 neutral sugars

Front 29

What is the main glycolipid of myelin?

Back 29

Galactocerebroside (neutral glycolipid)

Front 30

What is a complex glycolipid?

Back 30

Glycolipid with one or more sialic acid residues (N-acetyl neuraminic acid or NANA) with a net negative charge

Front 31

What is another term for complex glycolipids?

Back 31

Gangliosides

Front 32

Where are complex glycolipids most abundant?

Back 32

In plasma membrane of neurons, constituting 6% of total lipid mass (significantly less in other cells)

Front 33

How many types of gangliosides have been described?

Back 33

30 types

Front 34

What is ganglioside GMI?

Back 34

A cell surface receptor to which the bacterial toxin that causes diarrhea if cholera binds

Front 35

What are 2 characteristics of peripheral/extrinsic proteins?

Back 35

Relatively easy to isolate, sufficiently hydrophilic

Front 36

What are 2 types of extrinsic proteins?

Back 36

Extracellular extrinsic proteins and cytoplasmic extrinsic proteins

Front 37

What is an example of an extracellular extrinsic protein and what is it's function?

Back 37

i.e. large extracellular transformation sensitive protein (LETS) which function in cell to cell aggregation

Front 38

What is an example of a cytoplasmic extrinsic protein and what is it's function?

Back 38

ex. Spectrin which provides support for the RBC lipid bilayer

Front 39

What does denaturation do to intrinsic proteins?

Back 39

Destroys them

Front 40

What is a characteristic and function of intrinsic proteins?

Back 40

Usually hydrophobic and very difficult to isolate, function in transport of proteins, enzymatic activity, structure etc.

Front 41

What are 4 basic characteristics of membranes?

Back 41

Lateral movements of lipids are more rapid than proteins (I micrometer/sec), flip flop (transverse diffusion) of lipids but not proteins, rotation on axis for both lipids and proteins, asymmetry due to glycolipids for signal transduction

Front 42

What happens in transverse diffusion of lipids?

Back 42

Hydrophilic head moves through hydrophobic interior, thermodynamically not very favorable, may occur 1x every several hours

Front 43

Aerobically, glucose converts into what?

Back 43

2 pyruvate

Front 44

Anaerobically, glucose converts into what?

Back 44

2 lactate

Front 45

Due to selective permeability, which can enter mitochondria, pyruvate or lactate?

Back 45

pyruvate, lactate cannot enter

Front 46

True or false: mitochondria has its own DNA

Back 46

True, it is circular

Front 47

What percentage of ATP production occurs in mitochondria?

Back 47

95-98%

Front 48

Where does 2-5% of ATP production come from?

Back 48

Creatinine phosphate or glycolysis (anaerobic)

Front 49

What does CCR stand for?

Back 49

Creatinine clearance rate

Front 50

Mitochondria was first observed by whom in what year?

Back 50

Kolikor in 1880

Front 51

Most eukaryotic cells that obtain energy by aerobic metabolism contain what?

Back 51

Mitochondria

Front 52

Depending on cell type and metabolic state, what 3 things regarding mitochondria vary?

Back 52

size, shape and number (2,500 in hepatocyte, 25,000 in oocyte)

Front 53

What is the size and shape of a mitochondrion?

Back 53

rod-shaped, 0.2 to 1.0 micrometers

Front 54

Where are giant mitochondria often seen?

Back 54

In aging cells

Front 55

Does mitochondria divide dependently or independently of the cell?

Back 55

independently

Front 56

What kind of ribosomes do mitochondria have?

Back 56

70s

Front 57

ATP production in mitochondria

Back 57

Kreb's cycle in inner membrane and electron transport chain on cristae

Front 58

What is released during apoptosis?

Back 58

Cytochrome-C

Front 59

Mitochondria are a large generator of what?

Back 59

ROS (reactive oxygen species)

Front 60

Endoplasmic Reticulum

Back 60

smooth ER without ribsomes, rough ER with ribosomes, extend from nuclear envelope to plasma membrane, number of interconnected membranous sacs (cisternae), inflated vesicles or tubules, membrane is selectively permeable

Front 61

In what cells is ER less well-developed?

Back 61

spermatocytes, adipose cells, adrenal cortical cells

Front 62

In what cells is ER well-developed?

Back 62

in cells engaged in protein synthesis

Front 63

Rough ER

Back 63

usually flattened cisternae with ribosomes attached on its outer surface, functions in protein synthesis (post-translation and glycosylation of proteins)

Front 64

Smooth ER

Back 64

usually more tubular since it lacks ribosomes, functions in the synthesis of steroids, phospholipids and glycolipids

Front 65

How is smooth ER important in metabolism?

Back 65

In metabolism of lipids and glycogen including mobilization of glycogen to G-I-P and the the initial steps of breakdown of lipids

Front 66

Hepatocyte smooth ER

Back 66

Hydroxylation reaction: phenylalanine to tyrosine conversion

Front 67

Drug Detoxification

Back 67

Drug detoxification using cytochrome P-450 family in the hepatocyte SER, through hydroxylation drug solubility in water increases

Front 68

Example of carcinogenic effect of hydroxylations in SER

Back 68

ex. Aryl hydroxylases convert potentially carcinogenic compounds into their chemically active form; cigarette smoke activates aryl hydroxylase

Front 69

SER and RER can flip back and forth from one type to another: true or false?

Back 69

True

Front 70

Ribosomes

Back 70

large and small subunits, mRNA and RNA, blend of proteina nd RNA

Front 71

What is the function of ribosomes?

Back 71

Translation

Front 72

70s vs. 80s

Back 72

prokaryotic - 70s, and eukaryotic - 80s

Front 73

What does cis face of Golgi complex do?

Back 73

accepts transport vesicle with proteins from ER

Front 74

What does trans face of Golgi complex do?

Back 74

sends off secretory vesicle with proteins and binds with membrane, protein is expelled

Front 75

Where were Golgi complexes first identified and by whom?

Back 75

Golgi in 1898

Front 76

Where are golgi complexes very prominent?

Back 76

Vertebrate cells

Front 77

Where are golgi complexes very large?

Back 77

Secretory cells and nerve cells - smaller in muscle cells

Front 78

Maintenance of golgi complex depends on what?.

Back 78

Presence of nucleus

Front 79

What are the functions of the golgi complex?

Back 79

Glycosylation of proteins, secretion of glycoproteins, remodeling of membranes, synthesis of carbohydrates for glycosylation

Front 80

How does golgi recognize where carb will be attached?

Back 80

No idea, some sort of sorting mechanism

Front 81

Lysosomes

Back 81

membrane bound vesicle containing hydrolytic enzymes, discovered by Christian DeDuve in 1952

Front 82

Where are lysosomes most abundant?

Back 82

in leukocytes and cells that ingest large concentrations of extracellular materials, damaged cells, during apoptosis

Front 83

What is Pompe's Disease?

Back 83

Glycogen taken up by lysosome but not digested, skin cells rupture due to sun exposure leading to peeling etc.

Front 84

Nuclear Envelope

Back 84

outer and inner membrane with perinuclear space, plug is 70nm across (very large)

Front 85

What percentage of phospholipid bilayer can be cholestrol?

Back 85

30%

Front 86

What does compartmentalization do?

Back 86

Gives specificity

Front 87

Danielli Davson "Sandwich model"

Back 87

added proteins to lipid bilayer to account for surface tension

Front 88

3 components of signal transduction (glycoproteins)

Back 88

regulation via a regulatory protein, specificity (only one type of ligand can bind to receptor), amplification

Front 89

Which are active: primary or secondary lysosomes?

Back 89

Secondary (rich in hydrolytic enzymes)