Question | Answer |
The Plasma membrane is made of: | Phosolipid biylaer which consist of a Hydrophilic head and a Hydrophilic
tail |
A phospholipid consist of of | a glycerol, 2fatty acids, Phosphate |
Peripheral proteins are | are enzymes and supporting framework |
Integral or transmembrane
proteins: | transport and contain receptors |
Plasma membrane functions are: | Selective barrier
• Transport
- Active
- Passive
• Energy production (ATP)
- Electron transport chain (prokaryotes) |
Transport across membranes can be : | passive or active |
Passive Transport: | No energy needed
• Flow of transported substance
• From high to low concentration |
Active Transport: | – Energy needed
• Flow of transported substance
• From low to high concentration |
Passive transport or
Simple diffusion stops when: | reaching equilibrium |
Examples of passive transport are: | • Oxygen and carbon dioxide |
Passive transport
Facilitated diffusion is : | No energy required
From higher to lower concentration, i.e.
Mediated by transporter proteins
(permeases) |
Mediated by transporter proteins
(permeases) | • Water filled channels
• Ions, charged molecules and relatively large
molecules |
Osmosis: | Water (solvent) molecules move towards high solute
concentration across a selectively permeable
membrane |
Isotonic solution: | No net movement of water |
Hypotonic (Osmotic Lysis) | water moves into the cell and may cause the cell to burst if the wall is weak or damaged |
Hypertonic (Plasmolysis) | water moves out of the cell causing it to shrink |
Most bacteria cells live in_______? | Hypotonic environments |
Active transport requires ______________. | energy |
The concentration movement in Active transport is: | from low to high |
Transporter/carrier proteins
• Simple active transport | Transported molecule does not change |
Group translocation (unique to prokaryotes) | Modification of transported molecule as it enters the
cell |
The cytoplasm consist of: | –Water (~80%)
–Proteins
–Carbohydrates
– Lipids
– Inorganic ions
–DNA
–RNA
– Inclusions |
Nuclear area (Nucleoid) | No nuclear membrane
One chromosome attached to plasma
membrane |
species may have 2
chromosomes examples are: | Vibrio spp. Brucella spp |
The chromosomes contain: | About 3,200 genes
• Circular double stranded DNA (most)
– Linear double stranded DNA (a few, Borrelia spp.) |
Bacterial plasmids | Extrachromosomal genetic
material
• About 5 to 100 genes
• Not crucial for survival
• Great variety of genetic traits
• Antibiotic resistance,
enzymes, toxins, etc
• Transferable to other bacteria
• Major tool in genetic
engineering |
Bacterial ribosomes function: | to make protein |
Two subunits | 30 and 50 S = 70 S (each
made of rRNA and protein) |
T/F Bacterial ribosomes are smaller than eukaryote
ribosomes. | true |
Inclusions are: | • Reserve deposits (usually polymers)
–Lipids, sulfur
–Metachromatic granules
• Inorganic phosphate
–Polysaccharide granules
• Starch-like
–Gas
• Buoyancy |
Molecules concentrated in inclusions_____________. | reduce osmotic pressure |
Endospores are______ | Gram-positives |
Examples of Endospores are : | Bacillus spp.
• Clostridium spp |
Endorspores are: | Highly resistant dormant
form
– Highly dehydrated
– Multiple layers
– Rich in dipicolinic
acid/Ca+ complexes
– Provide heat stability |
eukaryotic cell | Larger and
more complex
than
prokaryotes
• 10 to 100 m
• Membranebound organelles |
Flagella in eukaryotic cells: | –Taxis
• Wave-like motion
very few and long in length |
Cilia in eukaryotic cells: | Movement of substances over the
surface of the cell
• Digestive and respiratory tracts
numerous and short |
Eukaryotic cells contain: | sterols (cholesterol) in the plasmis membrane |
Eukaryotes passive transport include: | • Diffusion
• Facilitated diffusion
• Osmosis |
Eukaryotes active transport have no | • No group translocation |
Endocytosis (unique to eukaryotes) | taking things substance into the cell |
Phagocytosis | particles |
Pinocytosis | liquid |
The Cytoskeleton consist of: | Microfilaments
– Intermediate filaments
– Microtubules |
Cytoskeleton functions include: | Shape
– Movement
• Entire cell
• Substances within the cell |
Nucelus: | Spherical to oval
•Contains linear DNA
•Replication
•DNA→DNA
•Transcription
•DNA→RNA |
Endoplasmic reticulum (ER) | Network of sacs next
to nucleus
• Synthesis of lipids
and proteins
• Rough ER
• Ribosomes
(80S)
• Smooth ER
–Lipid synthesis |
Rough ER | • Ribosomes
(80S) |
Smooth ER | –Lipid synthesis |
Golgi Complex | Receives ER
products
– Sorts
– packages
– delivers
(secretory
vesicles) |
Lysosomes | Derived from Golgi
complex
• Free spheres in
cytoplasm
• Contain powerful
digestive enzymes
• Numerous in white
blood cells |
Mitochondria multiply | on their own |
Double membrane
– Multi-folded inner
membrane
– Provides a large surface
for proteins involved in
cellular respiration (ATP
synthesis) | mitochondria |
Contains circular DNA
• Bacteria-like ribosomes
(70S) | mitochondria |