How can you manipulate fluidity of the cell? Name 4 ways.

Temperature effect

Saturation increases and decreases fluidity

Length of acyl groups, longer decreases fluidity

Cholesterol effect, it is a buffer and tries to keep it at the normal state

What 3 major components make up the ‘mosaic’ of the plasma membrane?

Phospholipids

Proteins

Carbohydrates

Which of the following organelles is NOT a member of the endomembrane system?

A. Golgi apparatus

B. Vacuoles

C. Peroxisomes

D. Lysosomes

C. Peroxisomes

What is the defining difference between prokaryotic cells and eukaryotic cells?

Prokaryotic cells do not have a nucleus and eukaryotic cells do

Which of the following is involved in protein synthesis?

A. Ribosomes

B. Smooth endoplasmic reticulum

C. Mitochondria

D. Nucleolus

A. Ribosomes

Which organelle receives, processes, and ships proteins?

A. The rough endoplasmic reticulum

B. The smooth endoplasmic reticulum

C. The Golgi apparatus

D. The mitochondria

A. The rough endoplasmic reticulum

Which statement best describes the lysosomes?

A. Powerhouse of the cell

B. Low pH of 5

C. Protein synthesis

D. Site of phospholipid synthesis

B. Low pH of 5

6. Which of the following is found in plant cells but not in animal cells?

A. Mitochondria

B. Plasma membrane

C. Rough endoplasmic reticulum

D. Plasmodesmata

D. Plasmodesmata

Where is the DNA material of a Prokaryote housed?

in nucleoid

Prokaryotes have no membrane bound organelles, but they do have protein based organelles, name 4.

Ribosomes

Cell wall

Glycocalyx (Capsule)

Flagellum

Where is the genetic material of a eukaryote found?

nucleus

What three things make up a nucleus?

Chromatin

Nucleolus

Nuclear Envelope

What can be found in a plant cell but not in an animal cell?

chloroplast

Central vacuole

Tonoplast

Cell wall

plasmodesmata

What three things make up the cytoskeleton?

Microfilaments

Intermediate Filaments

Microtubules

What can be found in an animal cell and not a plant cell?

Lysosome

Centriole

Flagella (some plant sperm)

What does the Nuclear Envelope consist of?

Outer Membrane

Inner Membrane

Nuclear Lamina

Ribosomes

Pore complexes

Gram Positive

Gram Positive – Crystal violet is trapped and cells appear purple. Bacteria that have a thick peptidoglycan layer. This is a simpler cell wall structure

Gram negative

(Crystal violet washes out of cells so they appear red or pink.) Bacteria have a thin peptidoglycan layer trapped beneath an outer membrane. Outer membrane contains lipopolysaccharides which can be toxic or cause immune response. Outer membrane resists antibiotic treatments.

1. Decomposers – Many bacteria serve to break down and recycle dead organic matter so it can be used again.

Many bacteria serve to break down and recycle dead organic matter so it can be used again.

1. Methanogens – Typically Archaea, release methane as a by-product of anaerobic respiration. (CO₂àH₂). Applications in sewer treatment, energy creation, major greenhouse gas, swamp gas.

Typically Archaea, release methane as a by-product of anaerobic respiration. (CO₂àH₂). Applications in sewer treatment, energy creation, major greenhouse gas, swamp gas.

1. Nitrogen fixers- N2 is the most plentiful form of nitrogen but it is generally useless to us biochemically. Some prokaryotes species can metabolize N2 into NH3 or NO2, sources that are useful to eukaryotes.

N2 is the most plentiful form of nitrogen but it is generally useless to us biochemically. Some prokaryotes species can metabolize N2 into NH3 or NO2, sources that are useful to eukaryotes.

Bacteria

More common, pathogens, peptidoglycans

Archaea

extremophiles, more closely related to eukaryotes

Integral protein

will go part way or all the way through the membrane

Trans membrane

anchored

Peripheral protein

Doesn't go into the membrane

glycolipid

sugar on lipid

oligosaccahride

glycoprotein

sugar on protein

oligosaccahride

Difference of Eukaryote and Prokaryote

Eu: Nucleus, Membrane bound organelles

Pro: Nucleoid, no membrane bound organelles

Parasitism

one species benefits (usually the symbiont) while the other is harmed but not killed

Commensalism –

one species benefits the other is not harmed or helped

Mutualism –

both host and symbiont benefit

Symbiosis –

an ecological situation in which two organisms live in close contact with each other. Host is larger organism. Symbiont is the smaller organism

Flagella

Microtubules serve as tracks for motor proteins

1. Kinesin Motors move away from centrosome
2. Dynein Motors move toward centrosome

Microtubles and dynine

1. Mutation –

this is the ultimate source of genetic variation. High reproduction rates, large populations, and short generation times allow bacteria to mutate quickly. Much of the population may be lost at anyone time but they are quickly replaced by more “fit” reproducers.

Transformation-

Bacteria have a built in mechanism for taking up and incorporating DNA from the outside. Survival mechanism. Useful in biotechnology

Transduction –

The process of prokaryotic genetic recombination mediated by phage infections

Conjugation –

Using pili, two prokaryotes (from different species even) can exchange plasmids. The donating plasmid must carry the F-factor in one of its plasmids or in its genome.

1. Nucleus

1. Ultrastructure: Double membrane (two lipid by-layers) called nuclear envelope, Nucleolus – dark spot in nucleus where ribosomes are made, Pore complexes – big transport tunnels through membranes.
2. Function: Houses cellular DNA

1. Rough ER

1. Ultrastructure: Extensive network of flattened sacs, Continuous with smooth ER, ribosomes bound to surface give a “rough” appearance
2. Function: Site for making membrane proteins and exported proteins, oligosaccharide tags added to proteins in lumen

1. Smooth ER

• Ultrastructure: Extensive network of tubules, Continuous with rough ER, no ribosomes
• Function: phospholipid synthesis, Ca²⁺ ion storage

Golgi Apparatus

• Ultrastructure: Cisternae – flattened membranous stacks, 5-12 distinct compartments,
• Function: Polysaccharide and oligosaccharide synthesis, Shipping & receiving center

Lysosome

• Ultrastructure: small to medium spherical organelles
• Function: breakdown of macromolecules. Acidic Internal pH 5 activates acid hydrolases. Acid hydrolases = enzyme that break down macromolecules into component subunits at acidic pH.

1. Microtubules

• Hollow rigid tubes, 25 nm diameter (steel pipes), polymer of subunits
• Organized from common point called Centrosome (centriole + proteins)
• (-) found near centrosome, (+) found distant from center
• Microtubules are dynamic continually grow and shrink
• Form compression resisting girders
• Microtubule function/locations – Spindle apparatus (pulls apart chromosome in cell division), Organelle structure, cilia and flagellum 9figure 4.12)
• Microtubules serve as tracks for motor proteins
  1. Kinesin Motors move away from centrosome
  2. Dynein Motors move toward centrosome
• Helps with motility by two tubes together and one pulling down and causing the other to bend.

1. Microfilaments (Actin Filaments)

1. 1. Two stranded, spiral filament (7 nm) (nylon rope), polymer of subunits
   2. Tension resisting network around cell interior (called cell cortex)
   3. Directional (+) end and (–) end.
   4. Dynamic – grows and shrinks
   5. Work in combination with myosin motor
   6. Location/Function
      1. Muscle fibers are made from actin and myosin bundles
      2. Cleavage Furrow – contractile ring splits cytoplasm in cell division

• Microvilli – tiny projection of plasma membrane increase surface area

1. Lamellopodia – the “oozing” effect of ameboid movement
2. Cytoplasmic streaming – cytoplasmic jetstream found in plants

Helps with motility by the hand grabbing motion or worm like motion

1. Intermediate filaments

• 32 stranded twisted filament (10nm) (steel cable)
• Most stable of the three fibers
• Most diverse – at least 32 different types
• Form a stable skeletal structure throughout the cell
• Important locations – nuclear lamina, keratins (Skin hair, nails, claws) axons.
• Not directional, no known motor proteins
• Tension resistance

Vacuoles

• Ultrastructure: Very large single membrane organelles. Much larger than vesicles, can occupy up to 80% of plant cell volume
• Functions:
  1. Storage of pigments, ions, waste, building blocks, defensive compounds
  2. Central vacuole in plants acts as a hydraulic press causing rigidity or turgor pressure. Central vacuole membrane called Tonoplast
  3. Phagocytosis – Vacuoles created when a cell “swallows” a large particle or bacterium for digestion.

Endomembrane system

Collection of organelles that are all related through direct contact or vesicular traffic. Includes nuclear envelope, ER, Golgi, Lysosomes, Plasma membrane, most vacuoles and vesicles