Module 3-4

Question 1

What are the two functions of a membrane

Answer 1

Keeping a barrier that regulates which molecules go in and out of the cell and protecting the cell from its surroundings and controls

Question 2

Explain the evolutionary origin of the mitochondria

Answer 2

Mitochondria evolved by way of symbiosis. A cell (ppe) that was presumably sick or weakened attempted to eat another cell (PPP) that was not weak and happened to be good at creating ATP. The PPP created extra ATP and gave it to the PPE. The health of the pie improved and it kept the PPP within to create ATP

Question 3

We are made up of _ water

Answer 3

50-70

Question 4

Facilitated diffusion uses a channel protein to let components move down their concentration gradient. (T/f)

Answer 4

True

Question 5

The Er is contiguous with the Golgi apparatus (t/f)

Answer 5

False

Question 6

The plasma membrane gets new lipids from:
• the lumen of the Er
• the lumen of the Golgi apparatus
• making new lipids at the plasma membrane
• the nucleus
• none of the above

Answer 6

None of the above

Question 7

A single pass trans-membrane protein that is an alpha helix can make a channel. (T/f)

Answer 7

False

Question 8

When a vesicle fuses with the plasma membrane the contents of the lumen of the vesicle are:
• ligands that enter the nucleus
• ligands that become the part of the plasma membrane
• ligands that are used in cell communication
• two of the above
• part of the nuclear pore complex

Answer 8

Ligands that are used in cell communication

Question 9

What is the difference between a triglyceride and a phospholipid?

Answer 9

A phospholipid has 2 fatty acids and a triglyceride has 3 fatty acids

Question 10

What is the difference between a single-pass transmembrane protein and a 7 - pass transmembrane protein?

Answer 10

A single pass TMP crosses the membrane only once and is not an open channel. A 7-pass TMP will cross the membrane 7 times and will create an open channel

Question 11

The Er is contagious with the nuclear envelope. (T/f)

Answer 11

True

Question 12

Cholesterol is_ to have in biological membranes

Answer 12

Good

Question 13

For a protein to enter the endoplasmic reticulum as part of the endoplasmic reticulum’s lumen or part of the ER’s membrane:
• the messenger RNA goes directly to the ER
• A ribosome binds to the mRNA sequence and a short stretch of protein is synthesized that contains a single sequence
• ribosomes at the endoplasmic reticulum bind to the protein
• is a random event and one day the protein could go to the ER and in another day the same protein could associate with a free polyribosome
• none of the above

Answer 13

A ribosome binds to the mRNA sequence and a short stretch of protein is synthesized that contains a single sequence

Question 14

If something is soluble in water and a shell of hydration forms around it, it is termed as

Answer 14

Hydrophilic

Question 15

What are the orphaned organelles from?

Answer 15

They are isolated from the endomembrane system

Question 16

Active transport uses ATP to move components in parallel with their concentration gradient, that is: from high concentration to low concentration. (T/F)

Answer 16

False

Question 17

Amino acids can be largely subdivided into two groups. What are the two groups?

Answer 17

Hydrophilic (polar), hydrophobic (non-polar)

Question 18

It is a simple matter (I.e), thermodynamically favorable) for a vesicle to form from the ER. (T/F)

Answer 18

False

Question 19

Draw a phospholipid and make sure the number of carbons are clearly identified

Question 20

Explain how the vesicles are carried from the Golgi apparatus to the plasma membrane

Answer 20

The Golgi apparatus makes a vesicle for proteins which travels on the micro tubule system then on the actin filament system to the plasma membrane (golgi apparatus makes vesicle, vesicle-> microtubule system-> actin filament-> plasma membrane

Question 21

Explain the evolutionary origin on the endoplasmic reticulum, Golgi apparatus, and vesicles

Answer 21

They are all believed to have formed from the invagination of the plasma membrane during the endomembrane system theory

Question 22

Heterochromatin does not exist in interphase nuclei. (T/F)

Answer 22

False

Question 23

The actin filament system is present in the nucleus. (T/F)

Answer 23

False

Question 24

Chromosomes are made out of Euchromatin. (T/F)

Answer 24

False

Question 25

Naked DNA does not exist in nature but scientists can make naked DNA in a test tube. (T/F)

Answer 25

True

Question 26

What does the nucleosomal core have in it (I.e., the basketball like structure in the slides)

Answer 26

8 histones (2 H2A, 2 H2B, 2 H3, 2 H4)

Question 27

Molecular motors run on which 2 cytoskeletal filaments?

Answer 27

Actin and microtubule filament systems have molecular motors

Question 28

Consider the geography of cell. Actin filaments are present in the cell’s ___ and the microtubules are present in the cell’s __

Answer 28

Plasma membrane, interior

Question 29

The diameter of an intermediate filament is 25 nm. (T/F)

Answer 29

False (10 nm)

Question 30

Molecular motors use ATP as the energy source to power the molecular motors. (T/F)

Answer 30

True

Question 31

To get into the nucleus a component has to have the correct signal sequence and pass through a nuclear pore. (T/F)

Answer 31

True

Question 32

Which cytoskeletal filament system lines the inside of the nucleus to protect it

Answer 32

Intermediate filament system

Question 33

Cilia and microvilli contain a similar number of parallel actin filaments. (T/F)

Answer 33

False

Question 34

The actin filament extends outside of the cell. (T/F)

Answer 34

False

Question 35

Where is the histone H1 found?

Answer 35

On the outside of the nucleosomal core protein “stapling” the DNA that’s wrapped around the protein to the protein