Chapter 4 Cellular Structures

Question 1

Microscopes

Answer 1

Light Microscopes- Show stained cells

Electron microscopes- Show the structure of killed cells

Question 2

Eukaryotic Cells

Answer 2

Contains membrane bound nucleus and cytoplasm
have organelles
ex. fungi, protists, plant cells and animal cells

Question 3

Prokaryotic Cells

Answer 3

• Lacks a nucleus and a membrane-bound organelles
• Genetic material is one continuous circular DNA and it lies in the nucleoid
• May have a flagellum to help the cell move

Question 4

Plasma Membrane

Answer 4

In the fluid mosaic model, the membrane is made up of the phospholipid bilayer
-Regulates the movement of substances moving in and out of the cell

Question 5

Molecules/Proteins found in the Plasma Membrane

Answer 5

Cholesterol- Stabilizes the membrane fluidity
Peripheral Protein- Proteins that are loosely associated with the lipid bilayer
Integral Protein- Proteins bound to the lipid bilayer that are amphipathic
These proteins form junctions between neighbor cells
- Serve as docking sites for proteins of the ECM or hormones
-Transport proteins in the membrane
- Form channels that allow the passage of certain ions

Question 6

Nucleus

Answer 6

home of the DNA
Control center of the cell
controls the cell’s ability to reproduce
- Nucleolus- Where the rRNA is made and the ribosomes are assembled

Question 7

Ribosomes

Answer 7

Sites of protein synthesis
Manufacture all the proteins required in the cell
Either free or bound to the Endoplasmic Reticulum

Question 8

ER

Answer 8

Continuous channel with the nuclear membrane
Extends to many regions of the cytoplasm
Rough ER
- Studded with ribosomes
- Makes proteins that are exported out of the cell
Smooth ER
- Lacks ribosomes
- Makes lipids, hormones, and steroids
- Breas down toxins

Question 9

Golgi Apparatus

Answer 9

Processes proteins
Modify/process/ and packages the proteins in vesicles
Sends these vesicles out of the cell

Question 10

Mitochondria

Answer 10

Convert organic molecules to energy (ATP)

Inner mitochondrial membrane folded into cristae

Question 11

Lysosomes

Answer 11

Membrane bound structures that carry digestive enzymes that breaks down old, worn out cells, debris, or large undigested particles

Question 12

Centrioles

Answer 12

Small paired cylindrical structures that are found in microtubule organizing centers
most active during cell division
produce microtubules, which pull replicated chromosomes apart to the opposite ends of the cell

Question 13

Vacuoes

Answer 13

Fluid filled sacs that store food, wastes, salts or pigments

Question 14

Peroxisomes

Answer 14

Detoxify various substances, producing hydrogen peroxide as a byproduct H2O2,
also have enzymes that break down H2O2 into water and oxygen
common in the liver and the kidney

Question 15

Cytoskeleton

Answer 15

Network of microtubules and microfilaments
Microtubules are made from the protein tubulin
Microfilaments made from the protein actin
Help in locomotive functions

Question 16

Prokaryote/Animal/ Plant

Answer 16

Prokaryote Plant Animal
Cell wall Yes Yes No
Membrane Yes Yes Yes
Organelle No Yes Yes
Nucleus No Yes Yes
Centriole No No Yes
Ribosome No Yes Yes

Question 17

Simple Diffusion

Answer 17

Small hydrophobic molecules are able to easily pass through the membrane

Question 18

Facilitated Transport

Answer 18

When proteins help solutes move from one side of the membrane to the other side

Question 19

Sodium Potassium Pump

Answer 19

Moved sodium out of the cell and moves potassium back into the cell
Pump relies on ATP to be able to do this

Question 20

Endocytosis

Answer 20

When the cell uses a portion of the membrane to engulf the substance
Pinocytosis: Cell ingests liquid
Phagocytosis: Cell taes in food
Receptor Mediated Endocytosis: Involves cell surface receptors when a particle or a ligand binds to receptors and the ligand is brought in by invagination

Question 21

Bulk Flow

Answer 21

One way of movement of fluids, brought upon by pressure

Question 22

Dialysis

Answer 22

Diffusion of solutes across a selectively permeable membrane

Question 23

Exocytosis

Answer 23

A cell ejects waste products or specific secretion products such as hormones by the fusion of a vesicle

Question 24

Cell Junctions

Answer 24

Form between two cells that come into close contact with eachother

1. Desmosomes- Hold adjacent cells tightly to each other
2. Gap Junction- Protein complexes that form channels in membranes and allow communication between cytoplasm or transfer of ions
3. Tight Junctions- Tight connections between membranes of adjacent cells no space between cells that seal body cavities