BacteriaChapter 2 Lesson 2

Cell Structure

Prokaryotic – genetic material is free in the cytoplasm rather than enclosed in a nucleus as in a eukaryotic cell

Cell Wall

Cytoplasm

DNA

Functions of Cell Parts

Cell Wall – protects the cell & provides structure & support

Cell Membrane – controls what materials come in and out of the cell.

Cytoplasm – fluid in the cell containing organelles and genetic material and allows structures to move within the cell

Ribosomes – organelles which produce proteins

Genetic material – DNA contains the information for all the cell functions

Energy & Reproduction Obtaining food:

Autotrophs using photosynthesis or chemosynthesis

Heterotrophs consume other organisms & often serve as decomposers in the environment

Reproduction

Binary fission: asexual reproduction in which one bacteria divides to form two identical cells.

Each cell receives a copy of genetic information

Conjugation: sexual reproduction in which one bacteria transfers some DNA to another bacteria.

Results in new combinations of genes

Endospores

Form when conditions are not favorable for bacterial growth

A thick-walled cell that can withstand extreme conditions for many years until conditions improve.

Bacteria’s Role in Nature

Oxygen production:

autotrophic bacteria that use photosynthesis supply oxygen to the atmosphere

Food production:

cheese & yogurt are examples of foods produced with the help of bacteria

Health/Medicine:

bacteria in your digestive tract help to digest your food and provide vitamins your body needs.

Bacteria are also used to produce medicine like insulin.

Environment:

bacteria help clean up oil spills and are natures recyclers.

decomposers break down dead organisms and return those compounds into the soil.

Nitrogen fixing bacteria live near plant roots and convert nitrogen gas to the nitrogen plants need to grow.

Disease Bacteria can cause disease in humans, other

animals, and plants

Common diseases in Humans:

Strep throat: Streptococcus pyogenesoften If left untreated, becomes scarlet fever and can affect the health of your heart

Pneumonia: Streptococcus pneumoniae Attacks the alveoli (air sacs) in your lungs

Tuberculosis: aggressive bacteria that attacks your lungs. Treating TB is difficult

Food poisoning: E. coli, Salmonella, Listeria are common causes