Cell Functions

Question 1

Different Cells have different

Answer 1

Shapes depending on their function

Question 2

The size of a cell is limited by its

Answer 2

Surface area-to-volume ratio

Question 3

As a cell grow its volume

Answer 3

Increase much faster than its surface area

Question 4

Cell Membrane (Plasma Membrane)

Answer 4

∙ Separates internal chemical reactions from external environment
∙ Regulates passage of material
∙ Made mostly of lipids & proteins

Question 5

Cytoplasm

Answer 5

∙ Jelly-like liquid that fills the inside of cell
∙ Composed of water, salts, & proteins
∙ Median for chemical reactions

Question 6

Nucleus (Nuclear Membrane)

Answer 6

∙ Filled w/ nucleoplasm & surrounded by a nuclear membrane
∙ Contains nearly all the cell’s DNA
∙ Site where DNA is transcribed into RNA

Question 7

RNA

Answer 7

∙ Carries protein-building instructions to the ribosomes
∙ Travel to cytoplasm through pores in nuclear membrane

Question 8

Chromatin (Chromosomes)

Answer 8

∙ When cell is diving the chromatin becomes a chromosome
∙ When not it remains as a threadlike material

Question 9

Nucleolus

Answer 9

∙ Manufactures subunits that makeup ribosomes

Question 10

Subunits

Answer 10

∙ 2 subunits: Large & Small
∙ Passes from nucleus - cytoplasm where they combine to form ribosomes

Question 11

Ribosomes

Answer 11

∙ Found free-floating by cytoplasm or attached to ER
∙ Most numerous cell organelle
∙ Composed of protein & RNA & not membrane-bound
∙ Site of protein synthesis

Question 12

Protein Synthesis

Answer 12

∙ Proteins assembled by ribosomes on rough ER
∙ Vesicles transport to GA & GA completes modifications
∙ Proteins are packaged in vesicles & leave GA
∙ Vesicle containing enzymes remain in cell as lysosomes

Question 13

Endoplasmic Reticulum

Answer 13

∙ Functions as intercellular highway
∙ Rough ER - covered w/ attached ribosomes & makes proteins
∙ Smooth ER - no ribosomes & makes lipids

Question 14

Golgi Apparatus

Answer 14

∙ Appears as stack of loosely connected membranes
∙ Function - modify, sort, & package protein that comes from ER
∙ Completes modifications before protein is shipped off

Question 15

Vesicle

Answer 15

∙ Small, spherical stack surrounded by single membrane
∙ Classified according to content
∙ Types include - transport vehicles, lysosomes, & peroxisomes

Question 16

Lysosomes

Answer 16

∙ From GA
∙ Filled w/ strong digestive enzymes & surrounded by think membrane
∙ Responsible for - destroying old organelles & destroying any debris that build up in the cell

Question 17

Peroxisome

Answer 17

∙ Not from GA
∙ Break down alcohols, fatty acids, kills bacteria, & produce hydrogen peroxide
∙ Converts hydrogen peroxide to water & oxygen

Question 18

Vacuole

Answer 18

∙ Storage area inside cell
∙ Stores water, salts, proteins, & carbohydrates

Question 19

Mitochondria

Answer 19

∙ Purpose - cellular respiration
∙ Have own DNA, inner & outer membrane, & carry out own replication
∙ 100s/1000s may be found in cell

Question 20

Cellular Respiration

Answer 20

∙ Process of converting glucose/sugar molecules into usable form of energy for cells

Question 21

Cristae

Answer 21

∙ Increase surface area for respiration

Question 22

Cytoskeleton

Answer 22

∙ Network of protein tubes & fibers that help cell maintain shape
∙Provides shape & support from inside
∙ 2 types of fibers: microfilament & microtubes

Question 23

Microfilament

Answer 23

∙ Solid, threadlike, protein structures
∙ Helps cells move, bear mechanical stress, & give support

Question 24

Microtube

Answer 24

∙ Functions - maintaining cell shape, separation of chromosomes during cell division, & formation of cilia & flagella

Question 25

Centrioles

Answer 25

∙ 2 short cylinders at right angle to each other ∙ Found near nuclear membrane ∙ Organize microtubules during cell division to form framework for separating chromosomes