The Cells Organelle Functions

Question 1

Mitochondria

Answer 1

Major site of ATP production in the cell
•Very active cells have more mitochondria
•The “power plant” of the cell

Question 2

Peroxisome

Answer 2

Performs reactions that detoxify toxic chemicals like alcohol
•Important in kidney & liver cells

Question 3

Ribosome

Answer 3

Site of protein synthesis
Assemble amino acid monomers into proteins

Only responsible for 1st level of protein structure (linear, not folded)

Question 4

Free ribosomes

Answer 4

float around in cytosol
•Make proteins for use within the cytosol itself

Question 5

Bound ribosomes

Answer 5

generally attach to rough ER
•Generally make proteins for export out of the cell

Question 6

Endoplasmic Reticulum

Answer 6

Large folded membranous system surrounding nucleus
•Includes rough ER & smooth ER

Question 7

Rough ER

Answer 7

Covered in bound ribosomes
•Site of protein folding into correct 3D shape
•Sends proteins to Golgi apparatus next

Question 8

Smooth ER

Answer 8

No bound ribosomes
•Nothing to do with proteins
•Where lipids are made
(Phospholipids, cholesterol, steroid hormones)

Question 9

Golgi Apparatus

Answer 9

Located between RER (rough endoplasmic) and PM
Sorts and packages proteins coming from RER
•Sends packages to PM (for exocytosis) or other organelles

Question 10

Lysosome

Answer 10

Contains enzymes called hydrolases
•Performs hydrolysis (break down reactions) of:
•Macromolecule nutrients that come into the cell
•Old/damaged organelles
•Even sometimes other cells (cancer cells/bacteria)

Question 11

Proteasome

Answer 11

Breaks down damaged/unwanted proteins into amino acids
•Amino acids can be reused to make new proteins
(Like a protein recycle bin)

Question 12

Cytoskeleton

Answer 12

Gives the cell its size, shapes, provides internal and structural support of the cell
-Motor proteins carry cargo along cytoskeleton “tracks”
-organized/directed by the centrosome

Question 13

Centrosome = a pair of centrioles

Answer 13

Cell not dividing- 1 centrosome (2 centrioles) per cell
-Organizes cytoskeleton from a single location near the nucleus

Cell is dividing- Duplicated to 2 centrosomes (4 centrioles)
-Reorganizes the cytoskeleton into the “mitotic spindle”
•Mitotic spindle evenly divides DNA & cytoplasm between 2 “daughter” cells

Question 14

Nuclear envelope

Answer 14

membrane enclosure around nucleus

Question 15

Nuclear pores

Answer 15

holes (passageways) in the nuclear membrane

Question 16

Nucleolus

Answer 16

where ribosomes are made in the cell

Question 17

Chromatin

Answer 17

loose threads of DNA when cell is not dividing (looks like yarn or spaghetti)

Question 18

Chromosomes

Answer 18

tightly wound DNA during cell division

Question 19

Gene

Answer 19

Functional unit of DNA; each gene codes for one protein

Gene = instructions for how to make ONE specific protein.