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what are the 3 major types of cells?
- 1-bacterial
- 2-archaeal
- 3-eukaryotic
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what are the four characteristics of life?
- growth
- reproduction
- responsiveness
- metabolism
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true or false?
cells are living entities surrounded by a membrane that are capable of growing, reproducing responding and metabolizing
true
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define organelles
specialized structures that act like tine organs to carry on the various functions of the cell
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true or false?
eukaryotes are usually large and more complex than prokaryotes
true
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what is glycolalyces?
a sticky substance that surrounds the outside of the cell
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what is glycocalyces composed of?
polysaccharides or polypeptide or both
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a loose, water-soluble glycocalyx is called?
slime layer
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what are some roles bacterial glycocalyx?
to protect the cell and plays a role in the ability of the bacteria to survive and cause disease
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what is flagella?
the structure responsible for the bacterial movement, long extensions that propel the cell through the environment
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what is flagella composed of?
- a long thin filament
- a hook
- a basal body
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what are the 3 flagella arrangements?
- 1-peritrichous-many flagellas
- 2-polar-single flagella in top or bottom side
- 3-tuft of polar-single hook with a couple of thinner flagella
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what is endoflagella?
bacteria that have the flagella built into the cell structure which causes the whole cell to move in a spiral like motion
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what produces "runs" in flagella?
the counterclock flagellar movement
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what causes"tumbles" in the flagella?
when flagellan align and spin together causing abrupt random changes in cell movement
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what does taxis mean in the motility of bacteria?
movement in response to stimuli
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what are the two forms of taxis?
- phototaxis=movement caused by light
- chemotaxis=movement caused by chemicals
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what is positive taxis?
the movement towards a favorable stimulus
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what is negative taxis?
the movement away from unfavorable environment
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define fimbriae
a sticky, bristle like projections-to adhere to one another or substances in the environment
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define Pili
tubes composed of a protein called pilin
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what is the function of Pili?
pili mediate the transfer of DNA from cell to another cell
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what does cocci mean?
it means spherical shape
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what does strepcocci mean?
single or in clains
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what does staphylococci mean?
clusters of cell wall
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what does sarcinae mean?
it means cuboidal packets
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what does bacilli mean?
it means rod-shaped cells typically in chains
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what are bacterial cell walls composed of?
peptidoglycan a complex polysaccharide
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what is peptidogycan composed of?
- its composed of two alternating sugar molecules.
- 1-NAG= N-acetylglucosamine
- 2-NAM= N-acetylmuramic acid
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how are NAG and NAM bonded?
they are bonded via covalent bonds
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cytoplamic membrane can also be referred to ask what?
cell membrane or plasma membrane
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what does isotonic mean?
when the solutions of either side of membrane experiences a net loss or gain of water
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what does hypertonic mean?
when the solutions are unequal one with a higher concentration of solutes
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what does hypotonic mean?
when there is a lower concentration on one side of the cell membrane
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what does uniport mean?
when only one substance can be transported across a cell membrance
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what does anti-porter mean?
when two chemicals are simultaneously transported across cell membrane in opposite direction
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what are symporters?
protein transporters that move two or more substances at the same time
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what is group translocation?
an active process that occurs only in some bacteria. the process involves a chemical change in a substance that is being transported
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what is cytoplasm
a general term used to describe the gelatinous material
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what is cytoplasm composed of?
cytosol, inclusions, ribosomes and many cells and a cytoskeleton
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what is cytosol?
the liquid portion of the cytoplasm
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what are inclusions?
a reserve deposit for lipids, starch and nitrogen, phosphate or sulfur
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what does sporulation mean?
the formation of endospores
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define nucleus
referred to as the control center because it carries the cells DNA
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what is nucleoplasm?
the semiliquid portion of the cell
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what are Nucleoli?
a specialized region where RNA is synthesized
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what is chromatin?
a threadlike mass of DNA inside the nucleus
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what is endoplasmic reticulum? or ER
is netlike arrangement of flattened hollow tubules
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what is the function of ER?
a transport system for the cell
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what are the two forms of ER?
- smooth endoplasmic reticulum SER
- rough endoplasmic reticulum RER
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what is the function of smooth endoplasmic reticulum? SER
it plays a role lipid synthesis and transport
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