Chapter 4 - A Tour of the Cell

Question 1

What is Cell Theory?

Answer 1

all living things are composed of cells which came from division of pre-existing cells

Question 2

What is a Prokaryotic?

Answer 2

• ->bacteria
• relatively small
• lack internal membrane-bound organelles
• rigid cell walls–>maintain shape

Question 3

What is a Eukaryotic?

Answer 3

• ->animals, plants, fungi, protists
• larger cells
• contains specialized membrane-bound organelles including central nucleus
• can be stabilized by cholesterol

Question 4

What is a membrane?

Answer 4

a physical barrier that separates the cytoplasm from the external environment, surrounds most organelles

Question 5

What is an organelle?

Answer 5

membrane-bound sub-cellular components where different metabolic reactions take place

Question 6

What is a water vacuole?

Answer 6

• plants only

- organelle that holds water

Question 7

What is a chloroplast?

Answer 7

• plants only *double membrane

- organelle that conducts photosynthesis

Question 8

What is a mitochondrion?

Answer 8

• organelle that is power plant for cell
• extract energy from food and turn it into ATP
• double membrane

Question 9

What are cristae?

Answer 9

folds in mitochondria that increase surface area –> maximize metabolic reactions

Question 10

What is a nucleus?

Answer 10

organelle that stores genetic information, reads it, and transfers it to cytoplasm as mRNA

• double membrane
• genes in nucleus store information here to produce proteins

Question 11

What does most of the work in a cell?

Answer 11

proteins

Question 12

What is a ribosome?

Answer 12

organelle that is responsible for protein synthesis (“translator”)

• -> bind to mRNA, scan, and translate gene code into protein (amino acids)
• made in nucleolus, assembled in cytoplasm

Question 13

What is a nucleolus?

Answer 13

an organelle within the nucleus that is responsible for transcribing and modifying DNA

Question 14

What parts are in the Endomembrane System?

Answer 14

1. Nuclear Membrane
2. Endoplasmic Reticulum
3. Golgi Apparatus
4. Lysosomes
5. Vacuoles

Question 15

Endoplasmic Reticulum

Answer 15

vast network of membrane covered “pipes,” serves as transport

Question 16

Smooth ER

Answer 16

• lacks surface ribosomes
• produces lipids
• helps liver cells detoxify circulating drugs

Question 17

Rough ER

Answer 17

• produce membrane proteins/secretory proteins

- some products dispatched to other locations by vesicles

Question 18

Transport vesicle

Answer 18

• sac made of membranes that bud off ER

- takes polypeptide from rough ER –> Golgi –> packaged into another vesicle from Golgi to final destination

Question 19

Lysosomes

Answer 19

membrane-bound sac of digestive enzymes found in animal cells, breaks down worn out cell parts used to build new cell structures/digest food to nourish cells
*only in animals

Question 20

What is the cytoskeleton?

Answer 20

network of protein fibers that carry out many functions (cell support, cell movement, structure)

Question 21

What is cytosol?

Answer 21

thick, jelly-like fluid that suspends cellular components

Question 22

What are chromosomes?

Answer 22

threadlike structure of nucleic acids and protein that carry genes made of DNA

Question 23

What is the plasma membrane?

Answer 23

what regulates traffic of molecules between cell and its surroundings

Question 24

What is the Golgi Apparatus?

Answer 24

receives, refines, stores, and distributes chemical products of the cell

Question 25

What is the central vacuole?

Answer 25

sac that stores organic nutrients in a plant cell, absorbs water and is half the volume of a plant cell

Question 26

What are the three internal compartments of a chloroplast?

Answer 26

1. stroma: thick fluid
2. grana: interconnected stacks, “solar power packs,” trap light energy and covert it to chemical energy
3. space between the two membranes that surround the chloroplast