Cellular Level of Organization

Question 1

Function of cell membrane?

Answer 1

• Protects cell
• Regulates materials entering/leaving cell

Question 1

Define:

Phospholipid bilayer

Answer 1

Two adjacent layers of phospholipids arranged tail to tail

The polar phosphate heads are attracted to water in ICF and ECF while the nonpolar tails keep fluid from entering the intermembrane space.

Question 2

What are the two types of integral proteins?

Answer 2

• Receptor proteins
• Glycoproteins

Question 3

Function of a receptor protein?

Answer 3

• Selectively binds molecules externally to induce internal changes
• Identify cell for recognition by other cells

Question 4

Define:

Glycoprotein

Answer 4

Protein embedded in cell membrane that has carbohydrate attached, extends into extracellular matrix

Question 5

Function of glycoprotein?

Answer 5

Help signal cell identity

Question 6

The structure of the lipid bilayer only allows what substance to pass via simple diffusion?

Answer 6

Small non-polar substances

Question 7

Define:

Diffusion

Answer 7

Movement of particles from area of high concentration to area of low concentration

Question 8

Define:

Osmosis

Answer 8

Diffusion of water

Question 9

Define:

Sodium-potassium pump

Answer 9

Type of active transport found in membranes of nerve cells

Question 10

Define:

Endocytosis

Answer 10

Ingests material by wrapping it with part of cell membrane and pinching it off to form intracellular vesicle

Question 11

What are the three types of endocytosis?

Answer 11

• Phagocytosis
• Pinocytosis
• Receptor-mediated endocytosis

Question 12

Define:

Exocytosis

Answer 12

Vesicles inside cell fuse with cell membrane, releasing contents of vesicle outside of the cell

Question 13

Function of rough endoplasmic reticulum (ER)?

Answer 13

• Protein synthesis

Question 14

Function of smooth endoplasmic reticulum (ER)?

Answer 14

• stores and regulates calcium
• metabolizes carbohydrates
• breaks down toxins

Question 15

Function of Golgi apparatus?

Answer 15

Sorts, modifies, and ships products from rough ER and produces lysosomes

Question 16

Function of lysosomes?

Answer 16

Break down and digest material

Question 17

Function of mitochondria?

Answer 17

Convert stored energy (glucose) into ATP

Question 18

Function of peroxisomes?

Answer 18

• Lipid metabolism
• Chemical detoxification
• Hydrogen peroxide production

Question 19

Function of cytoskeleton?

Answer 19

• Maintains structure
• Cell motility
• Cell reproduction
• Transportation of materials within cell

Question 20

What are the three types of fibrous proteins that make up the cytoskeleton?

Answer 20

• Microfilaments
• Intermediate filaments
• Microtubules

Question 21

Function of microtubules?

Answer 21

Maintain cell shape and structure

Question 22

Function of cilia?

Answer 22

Move constantly

Example: Lung cells have cilia to move dust away from lungs towards mouth.

Question 23

Function of flagella?

Answer 23

Locomotion

Only flagellated cell in humans is sperm cell.

Question 24

Function of microfilaments?

Answer 24

Help with muscle contraction and cell division

Question 25

Function of intermediate filaments?

Answer 25

* Maintains cell structure and shape * Resists tension

Question 26

Function of nucleus?

Answer 26

* Control center * Contains genetic material

Question 27

Function of nuclear pores?

Answer 27

Allow proteins, RNA, and solutes to pass between nucleus and cytoplasm

Question 28

Where is RNA produced?

Answer 28

In the nucleolus

Question 29

Chromatin is composed of:

Answer 29

DNA and proteins

Question 30

What are the four DNA bases?

Answer 30

* Adenine * Thymine * Cytosine * Guanine ## Footnote Adenine binds with thymine; cytosine binds with guanine.

Question 31

# Define: Transcription

Answer 31

RNA assembled by RNA polymerase from one DNA strand

Question 32

# Define: Initiation (transcription)

Answer 32

Promoter attaches to base, triggering transcription

Question 33

# Define: Elongation (transcription)

Answer 33

* RNA polymerase unwinds DNA segment * builds mRNA by aligning correct complimentary bases

Question 34

# Define: Termination (transcription)

Answer 34

* When termination sequence reached, RNA is separated from gene. * End of transcription

Question 35

# Define: Translation

Answer 35

Process of creating polypeptide from mRNA strand

Question 36

Initiation (translation)

Answer 36

* Ribosome binds to mRNA

Question 37

Elongation (transcription)

Answer 37

* Binding of correct anticodons from tRNA to codons on mRNA

Question 38

Termination (translation)

Answer 38

* Final codon on mRNA reached, stopping translation * Protein is released