BIO 203: Ch. 4

What is a prokaryote?

Single cell, lacks organelles, cell walls contain peptidoglycan, divide by binary fission

What is a eukaryote?

More than cell, contains organelles, cell walls are chemically simple, divide by mitosis

What are the basic shapes of bacteria?

Coccus (spherical), bacillus (rod), spiral (spirillum, vibrio, spirochete)

Arrangements of coccus bacteria?

Diplococci, streptococci, tetra, sarcinae, staphylococci

Arrangements of bacillus?

single, streptobacilli, palisades, diplobacilli

Arrangements for spiral?

What is the glycocalyx?

In prokaryotic bacteria, it is the outermost, viscous, gel-like layer composed primarily of polysaccharides

What are the two main forms of the glycocalyx?

1. Capsule: neatly organized, and tightly bound layer of polysaccharides adhered to cell wall

2. Slime layer: unorganized and loose layer of polysaccharides, glycoproteins, and/or glycolipids

What are the functions of the glycocalyx?

Protection and adhesion

What is the flagella?

1. Filament made of chains

2. Attached to the hook

3. Anchored to the wall and membrane by basal body

What are the arrangements of bacterial flagella?

a. peritrichous (lots all around)

b. monotrichous and polar (one at one end)

c. lophotrichous and polar (multiple at one end)

d. amphitrichous and polar (one at each end)

Function of flagella?

Motility (run or tumble)

What is chemotaxis?

move away or toward stimuli

What is a stimulus?

An attractant or repellent

What is phototaxis?

Movement away or toward a light source

What are axial filaments?

Also called endoflagella and causes cell to move in spiral motion (ex. spirochete)

What are fimbriae?

Hairlike appendages that are shorter, thinner, and straighter than the flagellum that adhere

What are pili?

Longer than fimbriae and only one (or two) per cell that facilitate transfer of DNA from one cell to another

What is a hypotonic environment?

More solutes inside cell than out → water rushes in to cell →cell explodes

What is a hypertonic environment?

Less solutes inside the cell than outside → water rushes out → cell shrivels up

What does a gram-positive bacterial cell wall have?

Multiple layers of peptidoglycan

What does a gram - negative bacterial cell wall have?

Only a single layer of peptidoglycan with an outer membrane

What are acid fast cell walls?

Have a thick peptidoglycan layer with a waxy lipid layer

What is the plasma membrane?

Viscous structure where proteins can move to function

What is simple diffusion?

Movement of solute from an area of high concentration to an area of low concentration

What is facilitated diffusion?

Solute combines with a transporter protein in the membrane (water channels)

What is active transport?

Requires a transporter protein and ATP

What is group translocation?

Requires a transporter protein and PEP (prokaryotes)

What is the cytoplasm in a bacteria?

Thick, aqueous, transparent, and elastic and accommodates the nucleoid, ribosomes, and inclusions

What does a bacterial chromosome look like?

Single, long circularly arranged thread of double - stranded DNA

What is plasmid?

Circular, double - stranded DNA that is transferred between cells (can be lost and not cause harm to cell)

What do ribosomes do?

SIte of protein synthesis and contains 2 subunits that contain rRNA and protein. (Prokaryotic: 70S = 50S + 30S)

What are endospores?

Gram + bacteria in adverse circumstances

What is sporulation?

Endospore formation

What is germination

Return to vegetative state

What is flagellum/a?

few and long projections

What is cilium/a?

numerous and short projections

How are flagella and cilia formed?

Anchored to plasma membrane via basal body, consists of 9 pairs and 2 array, moves in a wavelike manner

What is the glycocalyx?

Sticky carbs extending from animal plasma membrane bonded to proteins and lipids and helps to strengthen cell surface and adhesion

What is the function of plasma membrane?

Selective permeability and endocytosis

What is phagocytosis?

Pseudopods extend and engulf particles

What is pinocytosis?

Membrane folds inward, bringing fluid an dissolved substances

What is the cytoplasm?

Substance inside plasma and outside nucleus

What is cytosol?

Fluid portion of cytoplasm

What is the cytoskeleton?

Microfilaments, intermediate filaments, and microtubules

What is the nucleus?

Contains chromosomes (DNA)

What is the endoplasmic reticulum?

Rough ER + ribosomes = Protein synthesis, smooth ER is continuous with nucleus and deals with lipids

Eukaryotic ribosomes subunits?

have two subunits (80S = 60S + 40S)

What is the golgi complex?

Major collection and dispatch station of protein products received from ER

What is a Lysosome?

Digestive enzymes that breakdown molecules

What is a vacuole?

Some provide storage or bring food into cells

What is the mitochondria?

Involved in producing energy and cellular respiration