Biol 2201 Midterm 2

Front 1

Molecules that are with both hydrophobic and hydrophilic. Name 2 examples.

Back 1

Amphipathic.

Cholesterol, glycolipids

Front 2

What is the structure of a phospholipid?

Back 2

Polar hydrophilic head and nonpolar hydrophobic tail.

Front 3

When the hydrocarbon tail has no double bonds.

Back 3

Saturated

Front 4

What is the name of the spherical vesicle that phospholids form? Forms in the ECF of the bilayer.

Back 4

Liposome

Front 5

The molecule that fits in the spaces between phospholipids? What are the 2 characteristics?

Back 5

Cholesterol

-less permeable

-less flexible

Front 6

What are the 3 types of lipids?

Back 6

Phospholipids, cholesterol, glycolipid

Front 7

What defines and effects the bilayer composition?

Back 7

Hydrocarbon tail defines fluidity

- shorter tail = higher fluidity

- unsaturated hydrocarbon tail increases fluidity

Front 8

Describe where lipid synthesis occurs and the enzyme required.

Back 8

Takes place in the ER

- uses fatty acids to synthesize phospholipids

SCRAMBLASE transfers random phospholipids between monolayers

Front 9

Where do glycolipids obtain their sugar group?

Back 9

Golgi

Front 10

What are the 4 types of membrane proteins?

Back 10

Transport, Anchors, Receptors, Enzymes

Front 11

Proteins that are amphipathic, hydrophobic region lie in the bilayer. Their hydrophilic regions are exposed to each side of the membrane.

Back 11

Transmembrane

Front 12

Membrane protein are located almost entirely in the cytosol; have an amphipathic a helix exposed on the surface of the protein

Back 12

Monolayer-associated

Front 13

Describe the structure of transmembrane proteins.

Back 13

Contain a-helices that goes through the membrane bilayer.

- They contain hydrophobic side chains

- peptide bonds are polar

- Single pass (cross membrane once)

-Multi pass (multiple a helices crossing the membrane form channels)

Front 14

Describe flippase.

Back 14

Remove specific phospholipids from the side of the bilayer facing the exterior space and FLIP them into the monolayer that faces the ctyosol

Front 15

Describe the transmembrane protein B sheets and B barrels

Back 15

- B sheet is rolled into a B barrel

- in barrel = hydrophiliic, out barrel = hydrophobic

- amino acid side chains in barrel

- forms aqueous channel

Front 16

The sugar coating formed by all of the carbohydrate on the glycroproteins, proteoglycansm and glycolipids located on the outside of the the plasma membrane.

Back 16

Glycocalyx

Front 17

What are the 2 types of molecules that can be transported through simple diffusion? (7 examples gonches)

Back 17

Small nonpolar molecules - O2, CO2, N2, steroid hormones

Small uncharged polar molecules - H2O, ethanol, glycerol

Front 18

What are the 2 types of molecules transported using facilitated transport?

Back 18

Larger uncharged polar molecules

Ions

Front 19

What is the ion concentration of the cell membrane in terms of K+, Na+, and Cl-.

Back 19

K+ ~ high inside

Na+ ~ high outside

C- ~ high outside

Front 20

What are the characteristics of transporters?

Back 20

~ SPECIFIC molecule or protein must fit into its binding site

Front 21

What are the characteristics of channels?

Back 21

Molecules transfer based on their SIZE and CHARGE

Front 22

Describe the 2 methods of passive transport.

Back 22

~ molecules go through channels

~ passive transporter

Front 23

Describe the 2 characteristics of active transport.

Back 23

~ movement against concentration gradient

~ requires pumps (active transporters)

Front 24

Movement of water down its concentration gradient

Back 24

Osmosis

Front 25

Total concentration of solute inside the cell

Back 25

Osmolarity

Front 26

What are the 2 components of the electrochemical gradient?

Back 26

~force from the concentration gradient of the solute

~force from the membrane potential

Front 27

Describe the function of an aquaporin.

Back 27

A specialized channel that facilitates the flow water across the plasma membrane faster then regular simple diffusion.

Front 28

Describe the Sodium Potassium Pump.

Back 28

Na+ transport is couple by K+

~Ouabain is an inhibitor (inhibits K+ binding to pump)

Creates high Na+ concentration in the extracellular space

Front 29

Describe coupled transport.

Back 29

Symport - transfer solutes in the same direction

Antiport - transfer solutes in opposite direction

Front 30

Describe Ca2+ pump in the sarcoplasmic recticulum.

Back 30

Muscle cell is stimulated => influx of Ca2+ from sarcoplasmic recticulum into cytosol.

Front 31

Describe and label glucose transport in the gut.

Back 31

- symport transport

Front 32

What is cell respiration?

Back 32

Sugars are broken down and oxidized to produce CO2 and water

Energy is captured in high energy chemical bonds

Front 33

What is energy in an organism?

Back 33

Responsible for growth and development of cell

Front 34

What is catabolism?

Back 34

The breakdown of molecules into smaller subunits

- releases free energy

Front 35

What is anabolism?

Back 35

Smaller molecules build up into larger molecule

- free energy added

Front 36

What is the general overview of the oxidation of food and the net products?

Back 36

Glycolysis (in cytosol) => Citric Acid Cycle (inner mito mem(inm)) => Oxidative phosphorylation (inm)

Net results: Food + O2 => ATP + NADH + CO2 + H2O

Front 37

The ATP bond that stores lots of energy.

Back 37

Phosphoanhydride bond

Front 38

Glycolysis: location, total formula

Back 38

Location: Cytosol

Formula: Glucose + 2 ATP => 2 Pyruvate + 4 ATP + 2 NADH

Note: net atp is 2

Front 39

What is the function and role of kinase in glycolysis?

Back 39

Function: adds phosphate group to molecule

Gylcolysis: transfers phosphate group FROM ATP to a substrate in steps 1 & 3; transfers TO ADP to form ATP in steps 7 & 10

Front 40

What is the function and role of isomerase in glycolysis?

Back 40

Function: rearranges bonds within a molecule

Glycolysis: Steps 2 & 5 prepare molecules for chemical alterations coming

Front 41

What is the function and role of dehydrogenase in glycolysis?

Back 41

Function: Oxidizes a molecule by removing a hydrogen atom plus an electron

Glycolysis: Step 6, the enzyme generates NADH

Front 42

What is the function and role of mutase in glycolysis?

Back 42

Function: Shifts chemical group from one position to another within a molecule

Glycolysis: Step 8 - phosphate group is moved to transfer it to ATP from ADP in step 10

Front 43

What are the enzyme types involved in each of the 10 steps of glycolysis? (KIK AID KMEK)

Back 43

1) Kinase

2) Isomerase

3) Kinase

4) Adolase (gylcolytic enzyme)

5) Isomerase

6) Dehydrogenase

7) Kinase

8) Mutase

9) Enolase

10) Kinase

Front 44

What are the starting molecules, products and the location of fermentation in a muscle cell and in yeast?

Back 44

Starting Molecules: Pyruvate

Products: muscle ~ lactate & NAD+; yeast ~ ethanol, CO2 & NAD+

Location: Cytosol

Front 45

When does fermentation occur?

Back 45

breaks down sugar in absence of oxygen

Front 46

What is the starting molecules, products, and location of the process of pyruvate debcarboxylation?

Back 46

Starting molecule: Pyruvate

Products: CO2, NADH, Acetyl CoA

Location: mitochondria

Front 47

What are the starting molecules, products, and location of the process of fatty acid oxidation?

Back 47

Starting molecule: Fatty acyl CoA

Products: FADH2, NADH, Acetyl CoA

Location: Mitochondria

Front 48

What is the starting molecule, products, and location of the citric acid cycle?

Back 48

Starting Molecule: Acetyl CoA

Products: FADH2, NADH, GTP, CO2

Location: Mitochondria

Front 49

What are the enzymes involved in the 8 steps of the citric acid cycle?

Back 49

(LIDD KD HD)

1) Ligase (joins molecules)

2) Isomerase

3) Dehydrogenase

4) Dehydrogenase

5) Kinase

6) Dehydrogenase

7) Hydrolase

8) Dehydrogenase

Front 50

What is FADH2?

Back 50

A carrier of high energy electron and hydrogen

Front 51

What is GTP?

Back 51

Produced in the citric acid cycle. Transfers one phosphate group to ADP.

Front 52

What are the 2 anabolic reactions and the 4 intermediate products?

Back 52

Glycolysis: pyruvate

Citric acid cycle: Citrate, oxaloacetate, and succinyl CoA

Front 53

Which 2 organelles have double membranes, which organelle is largest?

Back 53

Nucleus & mitochondria

ER is largest

Front 54

What are nuclear pores?

Back 54

- Channels in the nuclear membrane

- enable communication with the cytosol

- protein binds to receptor => goes through nuclear pore

Front 55

Label the GTP hydrolysis cycle that drives nuclear transport.

Back 55

Front 56

What are the 3 major transport mechanisms?

Back 56

Nuclear pores, protein translocators, transport vesicles

Front 57

Label the mitochondrial protein import diagram.

What happens to proteins before entering mitochondria & chloroplast?

Back 57

Proteins unfold

Front 58

How do peroxisome proteins transport?

Back 58

Sequence of 3 a.a. signal transport to perox.

- receptor proteins in cytosol recognize transport sequence

- protein translocator

- no conformational change

Vesicular transport

Front 59

Describe protein transport to the ER.

Back 59

- most proteins destined for the golgi, lysosome, and endosome enter ER 1st

- ER signal sequence is 8 a.a. or more long

- signal recognition particle (SRP) binds to signal and ribosome

- SRP receptor on the ER membrane

Front 60

What are the 2 types of transmembrane protein?

Back 60

Single pass transmembrane protein

Double pass transmembrane protein

Front 61

Describe single-pass transmembrane proteins.

Back 61

~ has a N-terminal (red) that initiates transfer (cleaved off leaving the protein anchored to membrane)

~ Stop-transfer sequence (orange) that discharges polypeptide when it enters protein translocator

Front 62

Describe the double-pass transmembrane protein.

Back 62

~ has a start-transfer sequence (red, helps anchor protein to membrane, is recognize by SRP receptor)

~ has a stop-transfer sequence (orange, translocator discharges the sequences when it's reached)

~ neither sequence is cleaved off

Front 63

What is a locatization signal?

Back 63

Proteins that have nuclear localization signals are allowed entry into the nucleus

Front 64

What are the molecules involved in coated vesicle formation and what do they do?

Back 64

Clathrin coat - helps form vesicle

Dynamin - binds on neck, puts pressure on it and pinches it off

Front 65

What breaks down Ran?

Back 65

Ran=protein so a PROTEASE

Front 66

Contains hydrolytic enzymes which break down extracellular material and worn out organelles and is acidic because of proton pumps.

Back 66

Lysosomes

Front 67

Describe how LDL (low-density lipoproteins) enters the cell through receptor mediated endocytosis.

Back 67

1) LDL binds to LDL receptors on the cell surface & enters cell by clathrin-coated proteins.

2) vesicles lose their coating and fuse with endosome

3) In acidic endosome, LDL & receptor dissociate

4) LDL to lysosome and degraded to release cholesterol

5) LDL receptors return to membrane via vesicles