Biochem 2 Quiz 1

Front 1

True or False

1)Small Uncharged molecules can transverse the membrane easily by diffusion?

Back 1

True

Front 2

What are the 3 types of Sphingolipids that exist?

Back 2

1) Ceramides

2) Cerebrosides

3) Gangliosides

Front 3

Sphingolipids are built one of two amino acids, what are they ?

Back 3

1) Shingosine
2) Dihydroxysphingosine

Front 4

Name 2 Major functions of the cell membrane

Back 4

1) Communication

2) SELECTIVE permeability Barrier

Front 5

Cell Membranes contain _________ receptors on their surface that specifically bind to Hormones and Nuerotransmitters?

Back 5

Glycoproteins!!

Front 6

What are the 4 membrane functions mentioned in the text?

Back 6

1) Catalysis
2) Transport
3)Structural
4) Signal Recognition

Front 7

True or False?

Membranes comprimise approximately 75% of the average prokaryotic cell by weight ?

Back 7

False

Front 8

Biological Membrane vary in thickness between ___ and ____ nm's?

Back 8

5 - 10 nm

Front 9

The presence of lipids in biological membranes was first established by what scientist?

Back 9

Charles Overton in 1899

Front 10

What two dutch scientist studied RBC's and extracted their membranes to coin term "bi-layer" ?

Back 10

Gorter and Grendel (1925)

Front 11

All of the following are components of the prokaryotic membrane except?

a) Phospholipids
b) Proteins
c) Cholesterol
d) Carbohydrates

Back 11

Cholesterol!!

Front 12

True or false?

Several antibiotics selectively target bacterial cells that have cholesterol, while not affecting host cell that lack cholesterol??

Back 12

FALSE!!! (Pg 211 of your notes)

Antibiotics SELECTIVELY target cells LACKING cholesterol while not affecting host cells that are cholesterol rich

Front 13

What two scientist proposed the "fluid Mosiac Model?"

Back 13

Singer and Nicolson (1972)

Front 14

Protein migration has been studied using what technique in which mouse and human cells are fused?

Back 14

CELL FUSION TECHNIQUES

Front 15

Water is able to cross the biological membrane through what trans membrane channels?

Back 15

AQUAPORINS!

Front 16

True or False?

Mediated Transport may use PASSIVE transport?

Back 16

True. Only when the biological molecules are moving AGAINST their concentration gradient is when ATP is required.

Front 17

True or false
Ectoenzymes have gtheir active sites facing the cell interior ?

Back 17

False,

Ectoenzyme = Active site facing the outside of the cell

Endoenzyme = Active site facing the cell interior

Front 18

Classical G- Receptor Proteins possess ___ transmembrane regions and are termed _____

Back 18

Classical G Receptor Proteins posses seven transmembrane regions and are termed serpentine

Front 19

True or False

G Proteins may stimulate and inhibit adenylate cyclase activity?

Back 19

True

Front 20

Additional trimeric G proteins have been identified in brain neurons (Go), in smooth muscle of blood vessels (Gq or Gp), in olfactory sensory neurons (Golf)...Do these G proteins have an effect on adenylate cylcase? If not, how do these G proteins function?

Back 20

No, These special G proteins work by altering phospholipase C activity on the Beta subunit

Front 21

IN the resting cell, the G protein normally lies adjacent to the cell receptor in an inactive, off state, binding to what molecule?

Back 21

GDP, since its inactive

Front 22

The most well documented monomeric G protein is the product of the _____ gene?

Back 22

ras gene (also known as Ras.)

Front 23

Myelin Sheath is ____% lipid

Back 23

Myelin Sheath is 75% Lipid

Front 24

The inner mitochondrial membrane is ___ % protein

Back 24

IMM is 80% protein

Front 25

In order to flip from the outer leaflet to the inner leaflet , the phospholipid would have to cross into the inner hydrophobic enviroment using what energy yeilding enzyme?

Back 25

Flippases