CHAPTER 2 LESSON 2The Cell

CELL TYPES

2 Major Types Prokaryotic- Mainly bacteria or cells

without a nucleus Genetic material floats in the cytoplasm Do not have many of the common

organelles or cell parts.

CELL TYPES CONT.

Eukaryotic- Contain a nucleus Plants, animals, fungi, and protists Genetic material is generally found in

the nucleus and is surrounded by a membrane

Contain organelles with specific functions

CELL SHAPE AND MOVEMENT

Many sizes and shapes Related to function of the cell Example:

Human blood cell looks like a donut because it needs to bend and fold to fit into tight spaces.

Nerve cell- very long because it sends signals over long distances.

MAJOR PARTS OF THE CELL

Cell membrane Found in plant and animal cells Protects the cell from outside

substances Regulates or allows some substances

into the cell Made of a protein layer and

phospholipid layer

MAJOR PARTS CONT.

Cell wall Found in plant cells, bacteria, and

fungal and some protists Protects from attack of viruses and

harmful organisms In plants- provides support and

structure

CELL MEMBRANE AND CELL WALL

Cell membrane

Cell Wall

MAJOR PARTS CONT.

Cytoplasm- a fluid inside the cell that is mostly water but also contains salts and other molecules.

Also contains the CYTOSKELETON- a network of threadlike proteins join together Gives the cell shape and allows for

movement

CELL APPENDAGES

Used for movement Flagella- long, tail like appendages that

move back and forth

Cilia- short, hair like structures

NUCLEUS

Largest organelle in most eukaryotic cells Surrounded by two membranes- nuclear

membrane Directs cells activities Contains the genetic information

Human’s genetic information is found on 46 chromosomes

Kangroo’s genetic information is on 6 chromosomes

NUCLEOLUS

Makes ribosomes Often appears as a dark spot

MANUFACTURING PROTEINS

Ribosomes make proteins Ribosomes can be found floating in the

cytoplasm or attached to the endoplasmic reticulum (ER).

The ER extends from the nucleus to the cytoplasm

MANUFACTURING PROTEINS CONT.

Two types of ER Rough and Smooth Rough

Protein production Smooth

Makes lipids like cholesterol Helps remove harmful substances from the

cell

RIBOSOMES AND ER

PROCESSING ENERGY

Mitochondria are responsible for processing energy in most cells

Surrounded by two membranes Energy is stored in molecules called ATP Chemical processes release the ATP ATP= Adenosine triphosphate ATP is the fuel for cellular processes such

as growth, cell division, and material transport

MITOCHONDRIA

CHLOROPLASTS

Found in plant cells, algae, some protists

Use light energy to make glucose from water and carbon dioxide during photosynthesis.

Green pigment- chlorophyll

PROCESSING , TRANSPORTING AND STORING

The Golgi Apparatus or Golgi Body Prepares and Packages proteins into tiny

membrane bound ball like structures known as vesicles.

Transport materials from one part of the cell to another.

LYSOSOMES

Found in some animal cells Break down and recycle cellular parts Contain digestive enzymes

VACUOLES

Found in both plant and animal cells Animal cells tend to be small

Store food, water, and waste material Plant cells usually have one large one

called the CENTRAL VACUOLE. It stores water for support and shape of the cell.