Chapter 7 Notes:

The Cell

Core Standard: Describe features that are common to all cells and contrast those with distinctive features that allow cells to carry out specific functions.

 

Cell: the basic unit of living organisms.

 

History:

1665-Robert Hooke viewed thin slices of cork under a crude microscope and observed time hollow boxes. He called these boxes cells.

 

 

 

 

 

 

There are two types of cells:

Cell Type

Prokaryote

Description

Cells that have genetic material not contained in a nucleus.

Example(s)

Bacteria

Components

1.           Plasma membrane: controls what enters or leaves the cell.

2.           Chromosome: contains the DNA (the genetic info.)

3.           Ribosomes: make proteins.

4. Cytoplasm

Exception

Ribosomes are not true organelles because they are not enclosed in a membrane.

 

Cell Type

Eukaryote

Description

Cells that contain a nucleus in which their genetic material is separated from the rest of the cell.

Example(s)

Plants, Animals, Fungi, Protists

Components

See homework for the list of organelles.

 

 

 

 

 

 

Plant and animal cells differ in the following ways:

  

Type of Cell

Plant

Animal

Shape

Rectangular

Irregular or roundish

Boundary

Cell wall and cell membrane

Cell membrane only

Vacuoles

One large vacuole

Several smaller vacuoles

Chloroplasts/

Plastids

Present

Absent

Centrioles

Absent

Present

Cells structures and organelles involved in building proteins:

 

1.                       Ribosomes:  Produce proteins by following coded instructions that come from DNA.  Each ribosome is like a tiny machine or factory.

 

Note: Cells very active in protein synthesis contain large numbers of ribosomes.

 

2.                       Rough Endoplasmic Reticulum:  assembles proteins that are exported from the cell.

 

Ex.  Membrane proteins and proteins destined for lysosomes and other specialized locations within the cell.

 

3.                       Golgi Apparatus:  Modifies sorts and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell.