Biology lab 4

Prokaryotic cell desc.

• Unicellular

• Small

• More simple

Eukaryotic cell desc.

• Unicellular or multicellular

• Larger

• More complex

DNA in prokaryotic cells

Circular

DNA in eukaryotic cells

Linear

Storage of genetic material in porkaryotes

• Nucleoid region

• DNA is in the cytoplasm

Storage of genetic material in eukaryotes

• Membrane bound nucleus

• DNA is stored in linear chromosomes

• DNA is separate from the cytoplasm

Autotroph

Make their own food (often using energy from the sun)

Heterotroph

Consume autotrophs for food

Example of autotrophs

• Plants

• Algae

• Some bacteria

• Phytoplankton

Example of heterotrophs

• Animals

• Fungi

• Most protozoa

• Most bacteria

Cocci

Round/ spherical shape

Bacilli

Rod or pill shaped

Spirilli

Spiral shaped

Cocci bacteria

Bacilli bacteria

Spirilli shape

Gram negative shape

Gram positive bacteria

Gram negative bacteria desc.

• Has a lipopolysaccharide layer

• Has outer membrane

• Has rhin peptidoglycan layer

Gram positive bacteria desc.

• Has thick peptidoglycan layer

The green structure

Lipopolysaccharide

Top orange structure

Outer membrane

Purple structure

Peptidoglycan

Bottom orange structure

Cytoplasmic membrane

Gram negative bacteria color

Pink (Safranin)

Gram positive bacteria color

Purple (Crystal violet)

Similarities between gram negative and psoitive bacteria

• Have cytoplasmic membrane

• Have a peptidoglycan layer

Gram’s iodine

Mordant

Mordant

Reacts with crystal violet to form the crystal violet to form the crystal violet-iodine complex

Ethanol

Decolorizing agent

Grams iodine and ethanol are stains

False

Ethanol

• Dehydrates the thick peptidoglycan of gram-positive bacteria

• Dissolves the lipopolysaccharide layer of gram-negative bacteria

Controls of a gram stain

Gram positive and negative bacteria

Cyanobacteria

Photosynthetic prokaryote

Does chlorophyll a have bacteriophyll?

Yes

How is cyanobacteria arranged?

Linear filaments

Why is cyanobacteria called blue-green algae?

Phycobillins give it a blue hue

Thylakoid membrane

Thylakoid lumen

Cytoplasm

Cytoplasma membrane

Peptidoglycan layer

Outer membrane

Purpose of isolation streak plate

Decreasing bacterial concentrations enough to proliferate into discrete colonies after incubation period

Purpose of spread plate

Creates uniform surface of bacterial growth

Isolation streak plate

Spread plate

Gram negative bacteria

Gram positive bacteria