lesson 5

Question 1

Proteins exit from the ______ in transport vesicles destined for either the _____ _______ or another organelle of the endomembrane system.

Answer 1

golgi, cell surface

Question 2

______ cells isolate and organize their chemical reactions by aggregating proteins into multicomponent complexes that form biochemical ____________ with distinct _______.

Answer 2

prokaryotic, subcompartments, functions

Question 3

Transport vesicles carry ____ _____ proteins as well as other proteins and lipids that are part of the ______ membrane from one organelle to another.

Answer 3

soluble cargo, vesicle

Question 4

How do the interiors of the ER, Golgi apparatus, endosomes, and lysosomes communicate with each other?

Answer 4

a. by small vesicles that bud off of one organelle and fuse with another

Question 5

Where are most mitochondrial and chloroplast proteins made within the cell?

Answer 5

cytosol

Question 6

True or False: Proteins that are made in the cytosol and have NO signal sequence will remain in the cytosol rather than being excreted.

Answer 6

true

Question 7

True or False: The fate of any protein molecule synthesized in the cytosol depends on its amino acid sequence, which can contain a sorting signal that directs the protein to the organelle in which it is required.

Answer 7

true

Question 8

The _____ ________ signal on proteins destined for the nucleus is recognized by cytosolic proteins called _____ ______ receptors.

Answer 8

nuclear localization, nuclear import

Question 9

____ _____ ____ help direct a newly synthesized protein to a nuclear _____ by interacting with the tentacle-like _____ that extend from the rim of the pore into the cytosol.

Answer 9

nuclear import receptors, pore, fibrils

Question 10

True or False: The ER serves as a passing point for proteins destined for the golgi, endosomes, cell surface AND lysosomes.

Answer 10

true

Question 11

The _____-_____ sequence anchors the protein into the membrane.

Answer 11

stop-transfer

Question 12

Eventually a stop-transfer sequence forms a _-_______ membrane-spanning segment of the protein.

Answer 12

alpha-helical

Question 13

The movement of materials from the plasma membrane, through endosomes, and then to lysosomes describes which type of pathway?

Answer 13

endocytic

Question 14

Proteins that play a central role in the fusion of a vesicle with a target membrane are called what?

Answer 14

SNAREs

Question 15

By winding around each other tightly, ______ proteins pull the membrane _____ close enough to allow their ____ to flow together.

Answer 15

SNARE, bilayers, lipids

Question 16

Newly made lipids are supplied to the plasma membrane via the _____ pathway of _____

Answer 16

constitutive, exocytosis

Question 17

The process in which large particles like microbes and cell debris are consumed.

Answer 17

phagocytosis

Question 18

_____ can send material back to the plasma membrane, to a different _____ of the plasma membrane or onto the ______ for _____

Answer 18

endosomes, domain, lysosomes, degradation

Question 19

Which cellular compartment acts as the main sorting station for extracellular cargo molecules taken up by endocytosis?

Answer 19

endosomes

Question 20

This part of receptor-mediated endocytosis is the molecules packaged into vesicles for transport.

Answer 20

cargo

Question 21

This part of receptor-mediated endocytosis is the part that captures the correct cargo molecules.

Answer 21

receptor

Question 22

This part of receptor-mediated endocytosis is the part that mediated contact between the receptor and another component.

Answer 22

adaptin

Question 23

This part of receptor-mediated endocytosis is the thing that shapes the forming of vesicles.

Answer 23

clathrin

Question 24

_______ antibodies recognize the exact same ______ or part of an antigen. They are VERY specific.

Answer 24

monoclonal, epitope

Question 25

______ antibodies recognize different ______ of the same _____. For example mouse anti-rabbit protein X.

Answer 25

polyclonal, epitopes, antigen

Question 26

True or False: Internal membrane is present in bacteria and eukaryotic cells.

Answer 26

false, only eukaryotic

Question 27

Membranes are site of selective ________. We see the import and export of small molecules.

Answer 27

permeability

Question 28

There are many _____ in the membrane that extracellular _____ are able to bind to on the extracellular portion of it.

Answer 28

receptors, ligands

Question 29

The membrane is assembled in the ___. Proteins are assembled by the ribosomes based on the order of amino acids from the ______ which is determined by the DNA.

Answer 29

ER, mRNA

Question 30

True or False: There is no genetic sequence for a lipid; it is just the genetic instructions to build a lipid.

Answer 30

true

Question 31

Lipids are synthesized in the ER using ____ ____, there are also enzymes that synthesize phospholipids on the ______ face of the ER.

Answer 31

fatty acids, cytoplasmic

Question 32

Phosphate groups are at the hydro____ region of an amphipathic molecule and they have a ____ charge.

Answer 32

philic, negative

Question 33

Kinked tails means.

Answer 33

unsaturated

Question 34

Saturate means _____ tails.

Answer 34

unkinked

Question 35

The ____ molecule is what is directly attached to the phospholipid tails.

Answer 35

glycerol

Question 36

During _____ synthesis, water is being removed; we see the phosphate attached to the __ place so instead of the third chain we have a phosphate group.

Answer 36

dehydration, 2

Question 37

The ____ of lipids allows a bilayer to spontaneously assemble in an aqueous environment. This includes ______ interactions to minimize contact with water and formation of ______ spontaneously.

Answer 37

structure, hydrophobic, micelles

Question 38

Micelles: tails are on the (outside/inside).

Answer 38

inside

Question 39

In regards to fluidity, _________ means it contains a double bond and is _____ tightly packed aka _____ fluid.

Answer 39

monounsaturated, less, more

Question 40

In regards to fluidity, _____ means they are ____ tightly packed and thus ____ fluid.

Answer 40

saturated, more, less

Question 41

The ____ composition of various organelles are VERY different. Different organelles have their own different mix. As a result, different _____ can associate with these membranes supporting different functions.

Answer 41

lipid, proteins

Question 42

Lipid composition varies between _____ of membranes because the different '--' have different ______. For example, the plasma membrane, one side has an extracellular face and the other side has an intracellular face.

Answer 42

leaflets, functions

Question 43

Small nonpolar molecules include what 4 examples from class?

Answer 43

O2, CO2, N2, steroid hormones

Question 44

Small nonpolar molecules can cross ____.

Answer 44

freely

Question 45

Small _____ ______ molecules can get across but not as freely as small nonpolar molecules. The partial charges are fairly small.

Answer 45

uncharged polar

Question 46

3 examples of small uncharged polar molecules from class are what?

Answer 46

H2O, ethanol, glycerol

Question 47

Examples of large uncharged polar molecules include ___ ___, _____ and ______.

Answer 47

amino acids, glucose, nucleosides

Question 48

True or False: Large uncharged polar molecules may have nonpolar side chains but are still considered polar because of the backbone.

Answer 48

true

Question 49

What group cannot cross the membrane freely at all?

Answer 49

ions

Question 50

Movement of solutes across the membrane without the aid of a protein.

Answer 50

simple diffusion

Question 51

True or False: Simple diffusion sometimes uses channels or transporters.

Answer 51

false

Question 52

A form of passive transport that utilizes transport proteins to move solutes across the membrane.

Answer 52

facilitated diffusion

Question 53

A form of transport that moves solutes across a membrane against their concentration gradient.

Answer 53

active transport

Question 54

Active transport is carried out by ____ that harvest energy from ATP or an ___ ____ or light.

Answer 54

pumps, ion gradient

Question 55

______ transport by a _____ does NOT require a conformational change.

Answer 55

facilitated, channel

Question 56

_____ transport by a _______ DOES require a conformational change.

Answer 56

facilitated, transporter

Question 57

Water-filled pores through which substrates passively diffuse down their electrochemical gradient. They discriminate solutes based on ____ and _____

Answer 57

channels, size, charge

Question 58

Undergo a cycle of conformational changes linked to substrate binding and dissociation on opposite sides of the membrane. They bind with great _____

Answer 58

transporters, specificity

Question 59

What 2 things influence the passive transport of a charged solute across the membrane?

Answer 59

concentration gradient and membrane potential

Question 60

The membrane is a little _____ closer to the inside of the cell and a little _____ towards the outside of the cell.

Answer 60

negative, positive

Question 61

Glucose may be moved against its concentration gradient via a sodium _____

Answer 61

gradient

Question 62

If the sodium potassium gradient didn't work we would see ____ movement of glucose into the cell.

Answer 62

less

Question 63

The movement of glucose using the sodium potassium pump is an example of _____ active transport.

Answer 63

secondary

Question 64

In the example of Ca2+ in muscle cells, we needed ____ for the reuptake process because we would be moving Ca2+ _____ its concentration gradient.

Answer 64

ATP, against

Question 65

We may perform colocalization if we think a pump is not ____ correctly.

Answer 65

localized

Question 66

A mutation in the start or stop codon may cause the protein to be _____ incorrectly.

Answer 66

folded

Question 67

We can perform western blot to see if a protein is _____ and thus the pump is not working correctly.

Answer 67

degraded