CH 3 Cell Structure and Function

Question 1

What are the three parts of the cell theory? Who are the scientists who developed the cell theory?

Answer 1

1. All living things are composed of one or more cells
2. Cells are the basic units of structure and function in an organism
3. Cells come only from the reproduction of pre-existing cells
   The cell theory was created by Schleiden, Schwann, and Virchow

Question 2

Who was Anton van Leeuwenhoek?

Answer 2

-First person to observe living cells
-Made his own light microscope
-Observed microorganisms such as algae and protists

Question 3

Who was Robert Hooke?

Answer 3

-English scientist that studied nature using a light microscope
-Looked at thin slices of cork from bark on a cork oak tree
-Noted there were empty pores throughout the specimen that resembled cells the monks would live in
-Noticed other plant specimen had same organization of boxes
-First person to use term cell. He confirmed Leeuwenhoek’s observations

Question 4

Matthias Schleiden

Answer 4

Microscopist that stated how plants are composed of cells

Question 5

Theodor Schwann

Answer 5

Stated that animals are composed of cells

Question 6

Rudolf Virchow

Answer 6

Came to the conclusion that cells come from preexisting cells

Question 7

Prokaryotic Cells

Answer 7

-Smaller (1-5 um)
-Evolutionary older type of cell
-No membrane-bound organelles/nucleus
-Has a nucleoid (condensed circular DNA)
-Unicellular
-Bacterial cells
-Reproduces by binary fission
-Means “before nucleus”

Question 8

Eukaryotic Cells

Answer 8

-Larger (10-100 um)
-Younger type of cell (evolved from prokaryotes)
-Membrane-bound organelles/nucleus
-Has linear DNA in a nucleus
-Multicellular and unicellular
-Plant and animal cells
-Undergoes mitosis/meiosis to make new cells
-Means “true nucleus”

Question 9

How are ALL cells alike?

Answer 9

All cells have DNA, ribosomes, cytoplasm, plasma membrane, cell wall (plant eukaryotes), and flagella (animal eukaryotes)

Question 10

Plant vrs animal cells: What do only plant cells have?

Answer 10

Cell Wall, Central Vacuole, and Chloroplast (plastids)

Question 11

Plant vrs animal cells: What do only animal cells have?

Answer 11

Cilia, flagella, centrioles, and lysosomes

Question 12

Cell membrane (plasma membrane)

Answer 12

Function: Physical barrier for cell; Separates internal/external environments; selective permeability.
Location/Structure: Surrounding the cell, outer surface

Question 13

Cell wall

Answer 13

Function: Provides structure/support for plant cell
Location/Structure: Outside of cell membrane, made of cellulose

Question 14

Central vacuole

Answer 14

Function: Used for water/nutrient storage in plant cells
Location/Structure: no specific structure, but can take up majority of space inside cell

Question 15

Centrioles

Answer 15

Function: Organize microtubules of cytoskeleton during cell division
Location/Structure: Two short cylinders of microtubules

Question 16

Chloroplasts

Answer 16

Function: Contains chlorophyll which is pigment that makes plants green and is necessary for photosynthesis; each cell has multiple chloroplasts
Location/Structure: Oval shaped, with double membrane

Question 17

Cytoplasm

Answer 17

Function: Area within cell that contains the fluid, cytoskeletion, and the organelles
Location/Structure: Takes up the whole inside of the cell

Question 18

Cytoskeleton

Answer 18

Function: Hollow tubes made of protein, hold organelles in place, and maintain cell shape
Location/Structure: Radiate outward from center called centrosome near nucleus

Question 19

Smooth ER

Answer 19

Function: Allow for transport of substances throughout cell; Smooth ER doesn’t have ribosomes; functions in lipid synthesis
Location/Structure: Surrounding the rough ER

Question 20

Rough ER

Answer 20

Function: Allow for transport of substances throughout cell; Rough ER contains ribosomes; functions in protein synthesis
Location/Structure: Surrounding the nucleus

Question 21

Flagella/cilia

Answer 21

Function: Assist in movement. Cilia is short/present in large numbers, flagella is long extensions of cell, usually one that helps with cell moving
Location/Structure: Outside of cell

Question 22

Golgi apparatus (body)

Answer 22

Function: Packaging, modifying, and shipping of cellular products. Golgi “stamps” vesicles that move through it to where they need to travel to in the cell
Location/Structure: In cytoplasm near ER; system of flattened sacs

Question 23

Lysosomes

Answer 23

Function: Vesicles that break down/digest bacteria, old or damaged organelles
Location/Structure: Scattered in cytoplasm

Question 24

Peroxisomes

Answer 24

Function: Vesicles that produce hydrogen peroxide when they break down alcohol and engulf bacteria
Location/Structure: Scattered in cytoplasm

Question 25

Mitochondria (Look at notes for more details)

Answer 25

Function: Site of cellular respiration: the transfer of energy from organic molecules to ATP (ATP powers most of cell’s chemical reactions). Mitochondria has own DNA that it reproduces on its own. Location/Structure: Scattered in cytoplasm. There are two layers of membrane; outer and inner. Outer membrane holds cytosol, inner membrane has folds (cristae) where energy-harvesting chemical reactions occur

Question 26

Nuclear envelope (membrane)

Answer 26

Function: Keeps nuclear contents separate from rest of cell; allow for info to get into/out of nucleus when necessary Location/Structure: Surrounding the nucleus

Question 27

Nucleolus

Answer 27

Function: Dense area within nucleus; produces ribosomal RNA Location/Structure: Center of the nucleus

Question 28

Nucleus

Answer 28

Function: Control center of the cell; Houses and protects the cell’s genetic information; Contains instructions for the structure and function of the organism; Contains DNA; Filled with fluid called nucleoplasm Location/Structure: center of cell

Question 29

Ribosomes

Answer 29

Function: Sites of protein synthesis Location/Structure: Small spherical organelles in cytoplasm and can be on ER. Made of two subunits and are made of protein and RNA molecules. They are synthesized in the nucleus. Do not have a membrane.

Question 30

Vesicles

Answer 30

Function: Lysosomes contain enzymes that break down large molecules and help breakdown cells when its time for cell to die. Peroxisomes contain different enzymes they use to neutralize radicals and detoxify alcohol and drugs. Peroxisomes produce hydrogen peroxide as a product in their chemical reactions Location/Structure: Small sphere like sacs surrounded by single membrane (lysosomes and peroxisomes)

Question 31

Calculate surface area to volume ratio of a cube that is 2.5cm per side.

Answer 31

SA- L x W x 6 SA- 2.5 x 2.5 x 6 SA = 37.5 m^2 V- L x W x H V- 2.5 x 2.5 x 2.5 V = 15.625 m^3 Ratio- 37.5:15.625 Ratio = 2.4:1

Question 32

Explain the significance of surface area to volume ratio to the survival of the cell.

Answer 32

The greater the surface area and volume, the smaller the ratio. This means that the bigger the cell, the smaller the surface area and therefore less efficiency. The smaller the cell, the more efficiency.

Question 33

Explain how the organelles in a eukaryotic cell work together to perform all of the functions necessary for the cell to survive.

Answer 33

The nucleus holds the genetic information and controls the functions of the cell. The nucleus will first work with ribosomes and the endoplasmic reticulum during the process of protein synthesis. Specifically, the nucleus will supply DNA to the ribosomes to code for protein construction. Ribosomes can be located on the rough ER and are the site of protein synthesis. The ribosomes synthesizing the proteins will be attached directly onto the membrane of the ER. The rough ER is made up of a system of interconnected tubes that are covered with ribosomes. Next, the protein enzymes that are created within the rough ER are received by the Golgi apparatus. The Golgi modifies, concentrates, and packs the proteins into vesicles, like lysosomes. Vesicles are small, sphere-like sacs surrounded by a single membrane. The lysosomes are the vesicles that will break down the protein enzymes that it was given by the Golgi. The protein enzymes will be further processed and sorted in order to be transported to the plasma membrane. The plasma membrane is the physical cell barrier and has selective permeability. It may allow the proteins to pass through the membrane to eventually secrete from the cell.

Question 34

Microscope parts: head

Answer 34

May be turned to allow the eyepiece of the microscope to be rotated

Question 35

Microscope parts: Nosepiece

Answer 35

Revolves to allow you to switch objectives

Question 36

Microscope parts: High power

Answer 36

Magnifies 40X x 10X (ocular) times when clicked in place. Longest objective

Question 37

Microscope parts: Stage

Answer 37

Where the microscope slide is placed for viewing

Question 38

Microscope parts: Diaphragm

Answer 38

Controls the amount of light passing through the specimen

Question 39

Microscope parts: Eyepiece

Answer 39

Contains the ocular lens (10X)

Question 40

Microscope parts: Arm

Answer 40

One hand should grasp this part when carrying the microscope

Question 41

Microscope parts: Stage Clips

Answer 41

Anchors and moves slide

Question 42

Microscope parts: Course Adjustment Knob

Answer 42

Used for focusing in low and scanning power

Question 43

Microscope parts: Fine Adjustment Knob

Answer 43

Used for focusing in high power

Question 44

Microscope parts: Base

Answer 44

One hand should be under this part when the microscope is carried

Question 45

Microscope parts: Scanning Power

Answer 45

The shortest objective (4X)

Question 46

Microscope parts: Low Power

Answer 46

Low power objective; medium sized (10x)

Question 47

Microscope parts: Light Source

Answer 47

Where the light source is; light comes out of it