1 Rev of Cell Physio and Transport

Question 1

What is human physiology?

Answer 1

Science of the mechanical, physical, and biochemical functions of normal humans or human tissues or organs.

Question 2

Cell Theory

1. Also described as..
2. People who started this
3. States that:

Answer 2

1. the unifying concept in biology
2. Matthias Schleiden (botanist) and Theodor Schwann (zoologist)
   3.
   a. All organisms are composed of cells (Schleiden & Schwann).
   b. Cells come from preexisting cells (Virchow).
   c. smallest unit of life

Question 3

Eukaryotic cells

1. Groups with eukaryotic cells (4)
2. Diff from Prokaryotes? Importance of this difference?

Answer 3

1. Animal, Plants, Fungi, Protists
2. They have a membrane that delimits the nucleus and all other organelles. Important to compartmentalize reaction. Their PM is connected to membrane of all organelles all the way to the nucleus for communication.

Question 4

Plasma Membrane

1. Composition
2. Two classes or kinds of membranes

Answer 4

1. 2 layers of phospholipid;
2. A. Endomembrane system - allows organelles to communicate with one another via membrane and small vesicles
   B. Energy related organelles - basically independent & self-sufficient (e.g. mitochondria and chloroplast)

Question 5

Function and composition of the endomembrane system?

Answer 5

Restricts enzymatic reactions to specific compartments within the cell. It consists of nuclear envelope, membrane of the ER & GA, and vesicles.

Question 6

Anatomy of the nucleus
>Function?
>How do products exit the nucleus?

Answer 6

Covered by a membrane with nuclear pores (where products exit), command center of the cell, separated by nuclear envelope (from cytoplasm)

Question 7

Function of nucleolus?

Answer 7

For producing ribosomes for protein synthesis.

Question 8

Explain the central dogma.

Answer 8

Must include splicing, signal peptide cleavage to produce mature protein

Question 9

Product of ER?

Answer 9

Rough: Protein, Smooth: Lipid

Question 10

What is a golgi apparatus?
A. Characterize.
B. Functions? Indicate major function.
C. Mechanism?

Answer 10

A. 3-20 flattened curved saccules that has a cis and trans face
B. Major: Modifies proteins and lipids (e.g. attaching carbohydrate moiety); Other fxns: Packages them in vesicles then exocytosed/transported
C. Receives vesicles on ‘cis’ face then transported at ‘trans’ face

Question 11

Lysosome
A. Characteristic.
B. Origin.
C. Function.

Answer 11

A. Membrane bound vesicles in animal cells with low pH and lytic enzymes.
B. Produced by the Golgi Apparatus
C. Digestion of large molecules, recycling of cellular waste (energy efficient for the cell), apoptosis

Question 12

Peroxisome
A. Also known as
B. Similarities and differences with lysosome.
C. Function
D. Give an example of its location.

Answer 12

A. Microbodies
B. Similarities - membrane bound vesicle, contains enzymes
Differences - Peroxisome contains catalase
C. Catalyzes reactions that produce H2O2 (broken down to water and O2)
D. Liver cells (EtOH conversion to acetaldehyde)

Question 13

Endomembrane components

Answer 13

Lysosome, Peroxisome, ERs, Golgi Apparatus

Question 14

Mitochondria
A. Characterize.
B. In aerobic respiration, the _ and _ occur in the _ portions of the mitochondria.

Answer 14

A. It is bound by double membrane. It has cristae (infoldings of the inner membrane enclosing the matrix) and matrix (inner semifluid containing respiratory enzymes). Produces most ATP utilized by the cell.
B. Kreb’s cycle (mitochondrial matrix) and ETC (inner membrane of mitochondria)

Question 15

Organelle producing most of ATP utilized by the cell.

Answer 15

Mitochondria

Question 16

3 Filaments of the cytoskeleton

Answer 16

Actin, Intermediate, and Microtubules

Question 17

Actin Filament
A. Characterize based on shape
B. Functions.

Answer 17

A. Composed of globular and twisted proteins
B. 1. Maintains cell shape,
2. Supports microvilli
3. Involved in movement of cell and organelles
4. Involved in cytoplasmic streaming
5. For amoeboid movement
6. For muscle contraction

Question 18

Intermediate Filaments
A. Why is it “intermediate”?
B. Characterize.
C. Where is it usually found?
D. Functions.

Answer 18

A. Intermediate in size among the 3 cytoskeletal filaments.
B. Can be a monomer, dimer, or trimer. Usually rope-like
C. Usually found in cells that resist tension to help maintain rigidity.
D. 1. Support nuclear envelope
2. Tension-bearing elements to maintain cell shape and rigidity.
3. Anchor several organelles in place including nucleus.
4. Desmosomes

Question 19

Microtubules
A. Characterize.
B. Assembly is controlled by what? Most important of which is the?
C. Function.

Answer 19

A. Hollow cylinder made of 2 globular proteins (alpha and beta tubulin) forming a dimer that is arranged into tubular spirals of 13 dimers around an axis.
B. MTOC (Microtubule Organizing Center). Most important MTOC: centrosome (for mitosis)
C. Interacts with kinesin and dynein for movement of vesicles and organelles. *Also found in flagella

Question 20

Centrioles
A. Characterize.
B. No. and location in an animal cell.
C. Function.

Answer 20

A. Hollow cylinder made up of 9 overlapping microtubule triplets
B. 1 pair/animal cell located in centrosome at right angles.
C. Mitosis.

Question 21

Flagellum
A. Location
B. Characterize.
C. Function.

Answer 21

A. Sperm
B. In the basal body: 9 triplets with 1 in the middle; in the cross section: 9 doublets + 2 in the middle
C. For sperm movement (Using ATP can contraction allowing sperm to swim)

Question 22

What do you use _ for?
A. Vincristine
B. Taxol

Answer 22

A. For chemo; prevents polymerization of tubulin dimers = cells can’t divide esp. cancer

B. Taxol - stabilizes microtubules and arrests cells in mitosis

Question 23

What is Kartagener’s syndrome?

Answer 23

-autosomal recessive disorder
-missing dynein
»in cilia = impaired mucociliary transport = repeated lung infection
»sperm flagella = infertility

Question 24

The fluidity of the cell membrane depends on what factors?

Answer 24

A. Temperature = higher temp = higher energy = more fluid
B. More unsaturated fatty acids = more kinks = less packing = more fluid
*C. Cholesterol = stabilizes loose areas

Question 25

Composition of cell membranes

Answer 25

``` 1. Amphipathic lipids A. PPL B. Cholesterol C. Glycolipids 2. Proteins ```

Question 26

Which lipids in the PM are primarily in the outer leaflet? Inner?

Answer 26

Outer leaflet: CS (Phosphotidylcholine, Sphingomyelin) | Inner leaflet: SEI (Phosphotidylserine, phosphotidylethanolamine, phosphotidylinositol)

Question 27

Types and subtypes (based on function) of proteins in the cell membrane.

Answer 27

``` I. Integral or TM protein I.A.Transport I.A.1. Channels (passageways only) I.A.2. Carriers (involves conf change): either facilitated diffusion or active (1’/2’) transport I.B.Receptor ``` II. Peripheral

Question 28

What is Passive Transport?

Answer 28

With the concentration gradient, no energy needed, may use a passageway (channel) or just based on solubility of substance into the membrane

Question 29

``` Diffusion A. Describe. B. Passive or active? C. What affects diffusion? D. Example. ```

Answer 29

A. Movement of ions/molecules with the concentration gradient B. Passive Transport C. By Fick’s First Law of Diffusion (rate of diffusion across a plane is directly prop to concentration gradient across plane and area of the plane (J = DA(Ca-Cb)/deltaX = -D dC/dX); flux is always positive; D the diffusion coeff is not constant bc it is affected by the temp, concentration, pressure, solvent properties, and chemical nature of the diffusant. D. 1. Gas exchange (simple diffusion through the respiratory membrane; O2 enters the blood, CO2 enters alveoli) 2. Osmosis (diffusion of water across a selectively permeable membrane drawn by the osmotic pressure)

Question 30

Which will have a greater water attracting capacity - 3M sugar or 3M NaCl?

Answer 30

3M NaCl because it has 2 osmotic particles when it dissociates in water unlike sugar which only has 1.

Question 31

``` Tonicity A. Define. B. Kinds C. When RBC is subjected to the different kinds in B. What would happen? C. When a patient has ___, what do you give? 1. Hyperosmolar coma 2. Cerebral edema 3. Diarrhea ```

Answer 31

A. Ability of a solution to cause a cell to gain or lose water. B. Hypotonic - water goes to cell, isotonic - no net loss/gain, hypertonic - water drawn out of the cell C. Hypotonic - RBC bursts/hemolysis; Isotonic - normal; Hypertonic - shrinks/crenates D. 1. Hypotonic, 2. Hypertonic, 3. Isotonic

Question 32

Cell Membrane Channels Types

Answer 32

I. Leak II. Gated A. Mechanical B. Voltage

Question 33

Why is the inside of the cell more (-) than the outside?

Answer 33

1. K+ leak channels | 2. Na+-K+ pumps

Question 34

Describe the carrier-mediated transport mechanisms.

Answer 34

A. Facilitated Diffusion -passive transport, with conc. gradient., e.g. detection of high levels of glucose upon eating B. Primary Active -require ATP C. Secondary Active - uses energy from something else other than ATP such as concentration gradient - involves active transport of one substance (e.g. Na+) that establishes the concentration gradient - could be: Cotransport (Na+-Glucose cotransporters) or Countertransport (Na+-H+)

Question 35

What happens in receptor-mediated endocytosis?

Answer 35

A CSR binds tightly to the ligand forming the receptor-ligand complex —> then undergoes endocytosis forming a transport vesicle containing the complex —> Once cargo has been given to lysosome —> receptor will be recycled so energy efficient

Question 36

Phagocytosis vs. Pinocytosis vs. Exocytosis

Answer 36

Phagocytosis - part of the cell membrane extends around a particle and fuses it into the cell Pinocytosis - forms small vesicles and contain liquid rather than particles/take in water Exocytosis - secretory vesicles release their content - can be: 1. Constitutive - continuous release 2. Regulated secretion - in response to stimuli

Question 37

True or False. Explain. Every cell has the same DNA but not same product.

Answer 37

True, because each cell has a specific function e.g. vasopressin receptors in blood vessels vs. renal tubules.

Question 38

Gene Expression steps: 1. Cell makes a copy of a gene necessary to make a particular protein. 2. Converting copied info into a protein.

Answer 38

1. Transcription | 2. Translation

Question 39

What is homeostasis?

Answer 39

/Home/ = similar; /stasis/ = stable | -process of maintaining a stable environment suitable for sustaining life despite dynamic changes around and inside it

Question 40

Regulation of Blood Pressure - What happens when you have high BP? Low BP? - What is this process called?

Answer 40

High BP: Detected by baroreceptors -> signal medulla to decrease heart rate -> decrease BP Low BP: stimulate insulin release by pancreas -> insulin stimulates uptake in liver cells Process: Homeostasis