Topic 1D: Cell Organelles

Question 1

Cell Membrane

Answer 1

Structure:
- Made of phospholipids + proteins (lipid bilayer)
- Selectively permeable membrane
- Some have fingerlike projections called microvilli
Function:
- Separates cell from other cells + surrounding fluids
- Membrane allows some molecules but not others

Question 2

Mitochondria

Answer 2

Structure: Large and shaped like jellybeans, scattered throughout the cell
Function: To produce energy-rich molecules of ATP using energy (obtained by glucose breakdown)

Question 3

Ribosomes

Answer 3

Structure: Small and spherical, found scattered throughout cytoplasm OR attached to ER
Function: Sites of protein synthesis (to make) used by the cell or to be exported out

Question 4

Endoplasmic Reticulum (ER)

Answer 4

Structure:
- A system of double membranes that connects the nucleus to the cell membrane
- Ribosomes on surface = ROUGH ER
- Without = SMOOTH ER
Function: Transport materials through the cytoplasm

Question 5

Golgi Apparatus

Answer 5

Structure: Stack of membrane sacs
Function:
- receives protein molecules from ER
- protein packaging factory - golgi body wraps protein into single membranous envelope (vesicle)

Question 6

Vacuole

Answer 6

• the membrane-bound sac that stores food and waste materials
• IN PLANTS: Much larger than in animal cells and usually one big one when the cell has stopped growing (taking up more than 1/2 of the cell’s volume)
• holds large amounts of water/food and the plant waste products

Question 7

Lysosomes

Answer 7

• (similar to vacuoles) small and scattered throughout the cytoplasm
• contain chemicals that digest (break down) small particles of food entering the cell + worn out parts to be re-used

Question 8

Microtubules

Answer 8

• long/thin hollow protein tubes
• found within the cell (Cytoskeleton) and gives cytoplasm strength and shape

Question 9

Centrioles

Answer 9

• found in most animal cells (similar to soda straws)
• during cell division it makes up the part that splits up the chromosomes between the two daughter cells

Question 10

Cilia and Flagella

Answer 10

• hair-like extensions of the cell
• involved in cell movement and transport
  Cilia: Shorter and works in groups (more of them)
  Flagella: Larger and work individually (less of them)

Question 11

Chloroplasts

Answer 11

Large organelles that contain chlorophyll, a green pigment responsible for absorbing light energy for photosynthesis
- help plants make sugar from raw materials like CO2 or water

Question 12

Cell wall

Answer 12

• protects/supports the inside of the cell (like a barrier)
• made of cellulose, a complex carbohydrate

Question 13

Nucleus

Answer 13

• the brain of the cell: processes information and acts as the admin. center
• two major functions: stores cell’s hereditary material (DNA) + coordinates cell’s activities (ex. growth, protein synthesis, reproduction/cell division)

Question 14

Eukaryote

Answer 14

• Cells of advanced organisms that have a nucleus

Question 15

Prokaryote

Answer 15

• Unicellular organisms that lack a nucleus and membrane-bound organells

Question 16

Nucleoplasm

Answer 16

• the goo within the nucleus
• semifluid matrix that fills the inside of a eukaryotic cell

Question 17

Nuclear Envelope

Answer 17

• double-membrane that keeps whatever is inside the nucleus safe and pierced with nuclear pores
• regulates molecule passage between the nucleus and cytoplasm

Question 18

Nuclear pores

Answer 18

• perforates the nuclear envelope and holds the same function