BIO CH. 4

What are Cells

What are Cells

Cells are the basic units of life

Organisms can be…

single cells or multicellular

Plants, animals, and all other multicellular organisms are

a symphony of cells working in concert.

All organisms are composed of cells

Cell Theory

Calls are the basic units of structure and function in organisms

Cell Theory

Cells come from pre-existing cells because cells are self-reproducing

Cell Theory

Why are cells small

A higher ratio allows for better exchange of material into and out of
the cell.

Two Major cell types

Prokaryotic and Eukaryotic cells

Prokaryotic cells definition

“Before nucleus”

Eukaryotic cells definition

“true nucleus”

Examples or prokaryotes

Eubacteria and Archaea

Example of Eukaryotic cells

All multi celled organism

Where are prokaryotes found

Found in air, water, soil, in and on other organisms

Microbiome

The assemblage of prokaryotes on or in an organism

Where can we find a micro biome

Probiotics like yogurt, Can also be found in the gut

Why is bacteria good?

cultured bacteria makes insulin for humans to use. It is also necessary for nutrient cycling

3 parts of cell envelope - prokaryotes

Plasma membrane, cell wall, capsule

cytoplasm of prokaryote

A gel-like substance inside prokaryotic cells where cellular processes occur, such as DNA replication and protein synthesis.

nucleoid

Where the DNA is located in a prokaryote

ribosomes in prokaryotes

a site of protein synthesis

External structure of prokaryotes

Flagella (whip like tail used for locomotion) , Fimbriae (bristle like fibers that allow adhesion to surface)

difference between eukaryotic cells and prokaryotic cells

• Eukaryotic Cells:

  • Have a nucleus and membrane-bound organelles.

• Prokaryotic Cells:

  • Lack of a nucleus and membrane-bound organelles.

what do organelles in a eukaryotic cell do?

carry out unique functions within the cells

Endosymbiotic theory

The theory proposes that eukaryotic cells evolved from symbiotic relationships between different prokaryotic organisms.

Mitochondria and chloroplasts (M and C) are similar to bacteria in
size

evidence of the endosymbiotic theory

Both M and C have a double membrane.

evidence of the endosymbiotic theory

M and C contain limited DNA and its circular like prokaryotes

evidence of the endosymbiotic theory

M and C have their own ribosomes and make their own proteins

evidence of the endosymbiotic theory

RNA base sequence in M and C suggests prokaryotic origin

evidence of the endosymbiotic theory

Nucleus

most prominent structure and contains DNA

Ribosome

where protein synthesis occurs within the cell

endoplasmic reticulum

Metabolizes protein and lipids

Golgi apparatus

processes, packages, and secretes modified proteins

Lysosomes

digest material entering the cell and destroy nonfunctional organelles and
portions of the cytoplasm (autophagy)