Unit 4 Flashcards
Prokaryotes
Unicellular Organisms/Bacteria
No organized nucleus
Nucleoid
Prokaryotes nuclear region/Where genetic material stored
Ribosomes
- Synthesizes proteins
- Abundant in cytoplasm
Inclusion bodies
Storage molecules (extra DNA, glycogen, and plasmids)
Plasmid
- Self replicating extra chromosomal DNA.
- Can be shared across bacteria strains.
Flagellum
Used for motility
Pilus
- Sticks to surface of other cells
- Swap DNA with other cells
Capsule
Protective outer layer/coating
Prokaryote cell walls
- Semi rigid
- Gram-positive
- Gram-negative
Gram-positive
- Thick peptidoglycan layer
- No outer layer
- Cell membrane (phospholipid bilayer)
- Stains purple/easier to treat
Gram-negative
- Thin peptidoglycan layer
- Outer bilayer
- Cell membrane (phospholipid bilayer)
- Stains pink/Harder to treat
Eukaryotic cells
- Have a nucleus
- Membrane bound organelles
- Humans, plants, animals, fungi)
3 main parts eukaryotic cell
- Plasma membrane (cell membrane)
- Cytoplasm
- Nucleus
Plasma Membrane Characteristics
- Phospholipid bilayer
- Regulates intake/output for the cell
- Protects, forms links, identities the cell.
- Most molecules cannot pass freely (oxygen, carbon, steroid hormones can)
Aka - plasmalemma/Cell membrane
Glycoprotein
- Attach to proteins on the cell membrane
- Used to ID cell
- Sugar+protein
Glycolipid
- Used to ID the cell
- Attach to proteins on the cell membrane
- Sugar+lipid
Peripheral membrane proteins
Loosely associated with the bilayer
Integral membrane proteins
Transmembrane/bridge the lipid bilayer
The Cytoplasm characteristics
- Determines cell shape
- Comprised of cytosol and organelles
Cytosol
- “Brothy liquid” in cytoplasm
- Water, salts, and proteins
Organelles
- Tiny organs with essential cell functions
- Provide structural support, synthesis, storage, recycling, and energy production.
The Nucleus characteristic’s
- Control center of the cell
- DNA stored here
- RNA made here - sent out to make proteins
- Surrounded by nuclear envelope
Somatic cells
Cells besides sperm or egg, all share an identical copy of the same DNA.
Chromatin
DNA in use
Chromosomes
DNA packed in storage
Nuclear envelope
Membrane that is surrounding the nucleus
Amphipathic
Contain both polar and non-polar properties (phospholipid bilayer)
Cholesterol in Plasma Membrane
Regulates membrane fluidity
Aquaporin
- Transmembrane Protein which allows water molecules to pass through the membrane.
2.Typically found in epithelial tissue which secretes, kidneys, gastrointestinal organs and eyes.
Membrane protein types
- Ion channels
- Receptors
- Carriers
- Enzymes
- Linkers
- Cell Markers
Ion channels
- Transmembrane, passes ions
- Leakage channels
- Gated channels (ligand, mechanical, voltage)
Leakage channels (protein)
- Always opens
- ion channels
- transmembrane protein
Gated channels (protein)
- Need stimuli to open/close
- Ligand gated - extra cellular signal molecules
- Mechanical gated - membrane deflection/touch receptor
- Voltage gated - opened by electrical charges
Ligand
An extracellular signal molecule that binds to proteins/receptors
Receptor proteins
- Receive a ligand and makes changes within the cell
- Receptors can be ion channels
- GPCR (G protein coupled receptor) - metabotropic receptor which causes biological change once ligand binds
Carrier proteins
- Handle small polar molecules which cannot pass the cell membrane.
(e.g. glucose)
Enzymes
- Catalyze reactions
- Extracellular enzymes break large molecules into smaller molecules to transfer into the cell (e.g. lactose broken down)
Linker proteins
- Cells arranged into tissues bind together
- Integral and peripheral proteins perform the linking
Cell marker proteins
- Identify the cell
- Glycolipids - sugar+lipid (on red blood cells)
- Glycoproteins- sugar+protein (on almost all cells)
Passive Transport (4)
- Does not require activation energy
- Solute or solvent’s move with their concentration gradient (high to low)
- Follow principles of diffusion/entropy
Simple/facilitated diffusion, osmosis, and filtration
Simple diffusion
- Passive transport
- Small neutral/uncharged molecules move across the cell membrane
- Move high to low concentration
Facilitated diffusion
- Passive transport
- Charged ions that need a “bridge” (protein) to cross the cell membrane
- Move high to low concentration
Osmosis
- Water movement across a semi permeable membrane
- Water moves from high to low concentration
Osmotic pressure
- Force made by the movement of water through osmosis.
Tonicity
- Comparison of osmotic pressure of two solutions, (intracellular/extra cellular)
(Hypertonic, isotonic, hypotonic)
Hypertonic
- Concentration of water is higher inside the cell than outside the cell
- Water moves out of the cell causing shriveling (crenate)
Hypotonic
- Concentration of water is higher outside of the cell than inside of the cell.
- Water moves into the cell, can burst/lyse.
Isotonic
Concentration of water is equal inside/outside of the cell
Filtration
- Biological filter barrier for solutes and colloids (e.g. BP and osmotic pressure force materials through kidneys)
Kidney filtration molecular weigh cutoff
About 10,000 Da (10kDa)
Less than 10kDa passes, more than does not.
Active Transport
- Requires energy
- Moves ions against the gradient of concentration, low to high.
Primary, secondary, and vesicular.
Primary Active transport
- Na+/K+ pump or ATPase
- Maintains high sodium outside and high potassium inside.
- Uses ATP for energy
- 1 ATP, 3 Na+, 2 K+
- Low to high concentration
Secondary Active transport
- Uses energy from an Na+/K plus to move other solutes
- Symporter (co transporter) both flow in the same direction
- Antiporter (exchanger) flow in opposite directions
Vesicular active transport
- Moves large quantities of small things or things too large to pass through proteins.
- Endocystosis (into the cell)
- Exocytosis (out of the cell)
Endocystosis
Taking into the cell.
- Phagocytosis (cell eating)
- Pinocytosis (cell drinking)
- Receptor mediated Endocytosis
Phagocytosis
Cell eats large materials, surrounding in a vesicle and destroys.
Pinocytosis
Cell brings in liquid into vesicle
Receptor mediated Endocytosis
- Item of interest binds to cell surface protein receptor
- Clathrin (protein) changes shape to pull the item into a vesicle.
Exocystosis
- Expelling from the cell
- Signal molecule or digestive enzyme that is created in the cell that must be released
- Vesicle fuses to inner cell membrane, and then releases item to exterior.
Endotoxin
Prokaryotic outer layer of lipopolysaccharides that causes an abnormal immune response
