Cells Unit

Question 1

Cytoplasm

Answer 1

• 80-90% water

- function: fluid supporting the organelles

Question 2

Nucleus and nucleolus

Answer 2

-structure: chromosomes (proteins and DNA) surrounded by a nuclear membrane with pores
-function: DNA stores code of genetic info
Determined which proteins cells should make

Nucleolus

• dark section in nucleus
• lots of activity: site of RNA and ribosome manufacturing

Question 3

Mitochondria

Answer 3

• outer membrane, crustal membrane (inner folds), matrix (inside the cristae)
• function: powerhouse of cell = site for aerobic respiration = make ATP

Question 4

Chloroplasts (plastids)

Answer 4

• stacks of thylakoids surrounded by double membrane

- function: photosynthesis

Question 5

Ribosomes

Answer 5

• made of rRNA and proteins (made in the nucleolus)

- function: site of protein synthesis (amino acids)

Question 6

Endoplasmic Reticulum

Answer 6

• interconnected membranes
• function: importing and exporting materials

Rough ER
-involved in protein synthesis

Smooth ER

• produces lipids
• stores and releases calcium (for muscle contractions)
• helps detoxify chemicals in the liver

Question 7

Golgi Bodies

Answer 7

• structure: flattened cup shape membranes
• function: packages materials (proteins) for the cell to export
• found in high numbers in cells that secrete, example: enzymes from cells near digestive system
• helps make lysosomes

Question 8

Lysosomes

Answer 8

-membrane bound sacs of digestive enzymes
-if lysosomes break down
•lysis –> kills the cell
•important for finger/toe development, tail absorption in a tadpole, etc

Question 9

Peroxisomes

Answer 9

-breaks down hydrogen peroxide (H2O2), poison to cells

Question 10

Vacuoles

Answer 10

• structure: a space filled with water and dilutes surrounded by a membrane
• function: holds waste, food, or water
• large in plant cell, small in animal cell

Question 11

Proteins

Answer 11

• act as anchors in cell membrane

- relative position of proteins causes movement

Question 12

Cytoskeleton

Answer 12

-protein fibers that support and hold cell structures in certain places

Microtubules
-involved in attachment of chromosomes during cell division

Question 13

Centrioles

Answer 13

• found in pairs

- cylindrical organelles involved in pulling on micro tubules in cell division

Question 14

Flagellum

Answer 14

• threadlike projection

- complex arrangement of microtubules

Question 15

Cilia

Answer 15

• shorter hair like structures
• found in rows and mats
• in Protists: movement
• animals: in your lungs

Question 16

Cell walls

Answer 16

• found in bacteria, fungi, and plants

- rigid support and protection for cells

Question 17

Cell membrane (plasma membrane)

Answer 17

• phospholipid bilayer and proteins
• lipid: hydrophobic
• phosphate group: hydrophilic
• function: selectively permeable