Week 1 ( Cell Structure And Function)

Question 1

Microtubules function..

Answer 1

Stabilize the position, and movement of organelles.

Question 2

Prokaryotes ( one is incorrect)
A. Are the most numerous of all life forms.
B. Contain plasmids with their own DNA.
C. Contain a nucleons with its own DNA.
D. Are unicellular
E. Include a group known as the archaea.

Answer 2

C. Contain a nucleus with its own DNA.

Question 3

One of the statements is false about mitochondria:
A. The mitochondria cristae increase the inner surface area of the organelle.
B. The matrix of the mitochondria contain metabolic enzymes involved in energy production.
C. Respiratory enzymes are attached to the surface of cristae.
D. The mitochondria contain no DNA or RNA .
E. The mitochondria produce most of a cells ATP.

Answer 3

D. The mitochondria contain no DNA or RNA ( actually it has its own DNA)

Question 4

One of the major functions of both endoplasmic reticulum (ER) is the ….
A. Synthesis biomolecules
B.storages of genetic material for the cell.
C. Transport of biomolecules.
D. Storage of biomolecules.

Answer 4

A. Synthesis of genetic material.
C. Transport of biomolecules.
D. Storage of biomolecules.

Question 5

What molecules does the Smooth ER synthesizes?

Answer 5

Fatty acids
Steroids
Lipids

Question 6

A flagellum moves A cell through a fluid medium. What moves the fluid medium across the surface of cells that are. It free to move?

Answer 6

Cilia ( absent in bacteria and archaea.)

Question 7

Intermediate filaments…

MADE OF A VARIETY OF PROTEINS

Answer 7

Provide cells with strength
Stabilize the position of organelles
Do not transport materials within the cytoplasm.
Form the neurofilaments in nerve cells.

Question 8

Membranous organelle or inclusion?
Lysosome
Mitochondria
Ribosome

Answer 8

Lysosome- organelle
Mitochondria- organelle
Ribosome - inclusion

Question 9

Major differences between EUKARYOTIC And PROKARYOTIC cells.

Answer 9

1. Eukaryotic chromosomes are found inside the nucleus.
2. Eukaryotic cells are often larger
3. Eukaryotic cells contain extensive amounts of internal membrane.
4. Eukaryotic cells feature a diverse and dynamic cytoskeleton.

Question 10

List the components of the plasma membrane.

Answer 10

-Bilayer of phospholipids: hydrophilic heads interact with the aqueous medium outside and inside the cell, fatty tails are hydrophobic.

.cholesterol: expands the cell temperature and stabilizes the membrane.

Glycolipid and glycoprotein: cell recognition

-peripheral and integral proteins: signaling, adhesion of cells to each other and to the basement membrane, transport, enzymatic activity.

Question 11

What are the structural components of the cytoskeleton?

Answer 11

Microtubules (tubulin)
Intermediate filaments ( variety of proteins)
Microfilaments (actin)

Question 12

The nucleus; what does it contain and what isolates it from the surrounding cytoplasm?

Answer 12

Nuclear envelope or membrane (phospholipid bilayer)
Nucleolus (site in the nucleus where ribosomal RNA is TRANSCRIBED)
Nuclear pores
Chromatin ( containing DNA sequences chromosomes)

Question 13

How are the rough ER, Smooth ER, ribosomes, and Golgi apparatus.

Answer 13

They all make the endomembranous system: ribosomes existing in the rough ER synthesized the proteins, smooth ER synthesis steroids, lipids and fatty acids. It also breaks down poisonous lipids and creates a reservoir of ions Ca2+ ions. All of them go to the Golgi apparatus that checks them, stores and packages them in vesicles

Question 14

Origin and role of the mitochondria.

Answer 14

Endosymbiotic theory: prokaryotes evolved to create eukaryotic cells. Mitochondria is believed to be formed from a bacteria that somehow survived endocytosis by another species of prokaryote and became incorporated to the cytoplasm.
Role: it has two membranes. One is folded called cristae between it is the mitochondrial matrix. It’s role is to create adenosine triphosphate by burning glucose.

Question 15

What is the difference between lysosome and per peroxisomes.

Answer 15

Lysosomes perform intracelular digestion, they breakdown denitro
Peroxisomes has oxidase enzymes that function in neutralizing harmful free radicals. They detoxify.

Question 16

Explain the relationship between Microtubules, cilia, flagella, centrioles, spindle fibers , and the centrosome.

Answer 16

Microtubules are large, hollow tubes made of tubulin dimers that in the animal cell originate from the Microtubule organizing center (also called the centrosome) and grow outward, radiating throughout the cell.

• centrosomas contain two bundles of microtubules called centrioles.
• cilia and flagella are composed of microtubules .
• spindle fibers arise in the centrosome and attach to and move chromosomes during mitosis and meiosis(types of cell division ).

Question 17

Within cells, what other organelles other than the nucleus contain DNA and ribosomes?

Answer 17

Mitochondria

Question 18

What is the difference between translation and transcription?

Answer 18

Translation is the production of protein that occurs on a ribosome while transcription is the production of RNA using DNA as a template .

Question 19

What broadly is the enzyme RNA polymerase responsible for?

Answer 19

RNA polymerase Carrie’s out the transcription (production of RNA). It unwinds DNA and then adds complementary RNA nucleotides on the DNA template and joins them together.

Question 20

What are the base pairing rules for DNA and RNA?

Answer 20

For DNA A always binds with T and G binds to C. In RNA , G is complementary to C and A is complementary to U.