Chapter 3- Cells

Question 1

Plasma Membrane

Answer 1

Barrier that separates internal parts of cell from outside environment, Regulates what enters and exits the cell

Question 2

What are the components of the plasma membrane?

Answer 2

Phospholipids, Proteins, Cholesterol, Glycolipids / Glycoproteins

Question 3

Phospholipids

Answer 3

One of the three fatty acids is replaced with a phosphate group
Phospholipid Bilayer → when phospholipids are added to water, it spontaneously forms a bilayer
Molecule is polar in one area and non-polar in the other
Two Regions:
Head Region = polar (hydrophilic)
Tail Region = non-polar (hydrophobic)
Phospholipids make up the Bulk of the membrane & serve as primary barrier from inside and outside of cell → prevents bad things from coming in

Question 4

Proteins

Answer 4

Regulate which substances enter and exit the cell, Protein channels are embedded in the bilayer to allow substances to go through

Question 5

Cholesterol

Answer 5

Embedded between Some of phospholipids and control the elasticity of the cell membrane (ability to stretch/grow)

Question 6

Glycolipids / Glycoproteins

Answer 6

Only found on Outside of the plasma membrane
= carbohydrate (sugar) chains attached to either a lipid or protein
Function: cell to cell communication
Every person has Unique glycolipids / glycoproteins – why transplant rejection can occur

Question 7

Fluid Mosaic Model

Answer 7

Used to describe the properties of a plasma membrane, Consistently of plasma membrane is like olive oil

Question 8

Fluid

Answer 8

Constantly in motion
membrane is in Constant motion / phospholipids change places with neighbors constantly and move the proteins(but do not flip and cross the membrane)

Question 9

Mosaic

Answer 9

Different components
Four major components (phospholipids, proteins, cholesterol, glycolipids/glycoproteins

Question 10

Nucleus

Answer 10

Organelle = membrane bound structure with a specific function
Function: to house the DNA (information needed to produce proteins)
Double phospholipid bilayer (two membranes)
Proteins are NOT produced inside the nucleus (produced in ribosomes)
A filing cabinet
Produces RNA
Usually the largest organelle in the cell
DNA is used as a template to produce RNA and the RNA is transported out of the nucleus
DNA → RNA → Proteins

Question 11

Nuclear Envelope

Answer 11

Refers to the double phospholipid bilayer
Contains a large number of Pores – allows molecules of a specific size to freely cross the membrane

Question 12

Nucleolus

Answer 12

Dense area inside the nucleus responsible for producing Parts of the ribosome

Question 13

Chromatin

Answer 13

= DNA that is loosely coiled around proteins
Loosely packed means easy to find the information
Normal way that DNA is housed inside the nucleus
^^^ Chromatin is the form that DNA is typically found in

Question 14

Chromosome

Answer 14

= DNA that is tightly coiled around proteins
Only appear during cellular reproduction
Relatively inactive

Question 15

Cytoplasm

Answer 15

Everything inside the plasma membrane
Two Parts

Question 16

Cytosol

Answer 16

Liquid/watery portion of cytoplasm

Question 17

Organelles

Answer 17

Membrane bound structures with a function

Question 18

Ribosomes & Protein Synthesis

Answer 18

Ribosomes are Not surrounded by a membrane (still an organelle)
Made of – RNA & Proteins
Smallest of the organelles
Function: production of proteins
Parts of the ribosome are produced by the nucleolus
Can be free floating in the cytosol, but more likely are attached to another organelle

Question 19

Endoplasmic Reticulum (ER)

Answer 19

Phospholipid bilayer / One of the largest organelles / Attached to the nucleus
Function: internal cellular transport / production of lipids (smooth ER)
Primarily Transports – proteins, lipids
Two Types:

Question 20

Rough ER

Answer 20

Has ribosomes attached to it / Occurs near the nucleus

Question 21

Smooth ER

Answer 21

No ribosomes / Occurs away from the nucleus
Where most lipids are produces

Question 22

Golgi Apparatus (Golgi Complex)

Answer 22

Phospholipid bilayer / Large organelle / resembles a stack of pancakes / free floating
Function: to package internal materials for export out of the cell / produces lysosomes
Vesicles

Question 23

Lysosomes

Answer 23

Specialized vesicles produced by the Golgi apparatus that contain segregated enzymes (protein that breaks stuff down)
^^ The enzymes are packed inside a vesicles so that it is contained and does not break down things in the cell

Question 24

Mitochondria

Answer 24

Powerhouse of the cell → produces ATP
A double phospholipid bilayer
Inner membrane is larger than the outer membrane
Inner membrane is folded which is why it is larger

Question 25

Centrioles

Answer 25

Function: produce cilia and flagella / involved in cell division
No membrane
Only 2 per cell
Organize proteins into rope-like structures (do not produce)
The ropes are used to separate chromosomes during cellular reproduction

Question 26

Cilia

Answer 26

Function: movement
Rope-like protein structures found on the outside of the cell
short and more numerous
Hair like proteins on the outside of the cell

Question 27

Flagella

Answer 27

Function: movement
Rope-like protein structures found on the outside of the cell
longer and fewer
Tails

Question 28

Plasma Membrane Transport

Answer 28

Proteins help move things in and out of the cell

Question 29

Passive Transport

Answer 29

Crossing membrane without the use of ATP/energy

Question 30

Diffusion

Answer 30

Moving substance from high concentration to low concentration
Occurs until equilibrium is reached

Question 31

Osmosis

Answer 31

Diffusion of water

Question 32

Active Transport

Answer 32

Crossing membrane with input of ATP/energy
Can concentrate a substance on one side of the membrane

Question 33

Endocytosis

Answer 33

Bulk movement of a substance into the cell
Vesicle formation by the plasma membrane

Question 34

Exocytosis

Answer 34

Bulk movement of a substance out of the cell
Rupture of a vesicle when it fuses with the plasma membrane

Question 35

Vesicle

Answer 35

A structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer