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Which membrane proteins are responsible for connecting cells to each other?
Attachment proteins
Ribosomes are the site of synthesis of ?
Proteins
Cytoskeleton
Support structure of a cell so organelles don't float around freely.
Plant cell
1, Isotonic Solution. stays the same, no change. 2. Hypotonic- water moves in cell does not burst, it swells but is contained due to the cell wall. 3. Hypertonic- water moves out from the cell and the cell shrivels up.
Plasma Membrane
1. A phospholipid bilayer boundary between the living cell and its surroundings. 2. Regulates the flow of material that goes in and out of the cell. 3. Helps the cell interact with other cells
3 main components of modern cell theory Rudolf Virchow's ideas 1850
1. All living organisms are composed of one or more cells. 2. The cell is the smallest functional unit of life. 3. All cells come from pre-existing cells.
3 parts of the passive transport
1. Diffusion- that is no membrane Solute. 2. Osmosis - that is the diffusion of water thru the membrane. high to low, left to right. 3. Facilitated Diffusion- that uses a carrier protein to move the membrane.
2 parts of the active transport
1. Exocytosis- which is transport of bulky material. 2. Endocytosis - which is broken into 3 parts. 1. Pinocytosis- which is cell drinking. 2. Phagocytosis-which is cell eating. 3. Receptor Mediated endocytosis- which uses a specific substance.
Animal Cell
1. Isotonic-Same inside cell & outside cell. when a cell is immersed in Isotonic solution nothing changes. 2. Hypotonic- More water less Solute- Water goes into the cell causing the membrane to burst. 3. Hypertonic- less water and more solute- The cell will shrivel up.
Prokaryotic
Before the nucleus
Smooth ER
Does not have Ribosomes. Synthesis of Lipids
Cell Wall
Rigid protective layer outside the plasma membrane. Composed of cellulose.
Osmosis
The diffusion of water across a membrane
Transport of molecules
1. Passive- No energy is needed to move the molecule. high to low concentration and moves down the gradient. 2. Active- needs energy to move the molecule(ATP) low to high concentration and moves against the gradient.
Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the phospholipids point our and the tails point to each other?
1. The heads are attracted to the water inside and outside. 2. The tails are repelled b the aqueous environment.
Main functions of the Plasma Membrane
1. to isolate the cell's internal environment from the external environment. 2. Regulate the flow of materials in and out of the cell. 3. All interaction with other cells.
The cytoplasm of a certain cell, such a a neuron, already has a high concentration of K+ ions. How can k+ ions continue to enter the cell?
Active transport
Beaker A has a 10 % sucrose solution and beaker B has an 8% sucrose solution.
Beaker A is hypertonic to beaker B
Rough ER
Contains Ribosomes on it outer surface. Synthesis of proteins
Pathway of information flow in the cell
DNA-RNA-Protein
The net movement of molecules from a high concentration to a low concentration is best described as?
Diffusion
What would happen if the plasma membrane were composed solely of phospholipids and no proteins?
Diffusion and osmosis would continue to occur
Recognition proteins are most important for?
Distinguishing foreign cells from self cells.
Difference between the light and electron microscope
Electron microscope uses beams of electrons. Light microscope uses lenses.
Chloroplast
Energy producing organelles only found in plant cells. Uses energy from sunlight to make sugars.
The blood plasma of a man who drinks saltwater will become______ to his red blood cells, whereas the red blood cells will be________ to the blood plasma
Hypertonic and Hypotonic
Central Vacuole
Largest organelle. The storage center that helps regulate the amount of water inside a cell.
Endoplasmic Reticulum ER
Main manufacturing center of cell.
Lysosomes
Membrane enclosed sac. breakdown substances such as waste products, or old organells
Endomembrane System
Network of organelles that make and distribute cell products.
Ribosomes
Organelles responsible for making proteins
The process whereby white blood cells engulf bacteria is termed?
Phagocytosis
Mitochondria
Produces ATP. Primary site for cellular respiration. Where energy from sugars and other food molecules are converted to ATP.
Describe the interrelationship of structure and function among the RER, Smooth ER and the Golgi complex
RER makes proteins and phospholipids to use as membrane components, it then goes off and travels to the Golgi apparatus and then out. The SER is where the synthesis of phospholipids and cholesterol are used to make membranes.
How does the plasma membrane act as a gatekeeper for a cell?
Separate internal and external environments, regulate the exchange of substances between external environment and the cytoplasm, and communicate with other cells.
ATP
Small molecules which cells can use for energy to fuel most forms of work.
Inhibitors
Stop an enzyme from doing its job. 2 types of Inhibitors. 1. Competitive- these inhibitors attach at the active site on the enzyme. 2. Non Competitive- these inhibitors attach at the allosteric site of the enzyme.
Which cellular component packages hydrolytic enzymes and forms lysosomes?
The Golgi complex
If all lysosomes in a cell ruptured, what would occur?
The macromolecules in the cell cytosol would begin to degrade.
Osmosis/Simple diffusion
They are both passive processes. However osmosis refers tot he movement of water down its concentration gradient across a semipermeable membrane. No membrane is required for simple diffusion.
what is the evidence that mitochondria and Chloroplast were once free living organisms?
They produce ATP They contain their own DNA
Cells that line the intestine have a highly folded plasma membrane on the absorptive side of the intestine because
This will increase surface area to volume ration.
Why are cells so generally so small?
To maintain sufficient surface area for the exchange of nutrients and wastes with the external environment
What buds off the Golgi complex?
Vesicles
Both plant cells and animal cells will swell if placed in a hypotonic solution. However only the animal cell will burst. Explain
Water goes into both cells due to osmosis. The animal cell will continue to take the water as long as the solution is hypotonic causing the animal cell to eventually burst. Only the plant cell is protected by the cell wall while taking in water the cell will expand but not burst. The cell wall will exert pressure back on the cell and water will be prevented from entering, therefore it will not burst.
Golgi Apparatus
Where proteins are modified, tagged, and sent to the appropriate areas of the cell
I biological membranes, the phospholipids are arranged in?
a bilayer with the fatty acids pointing toward each other.
How are plasma membranes best described?
a double layer of phospholipid molecules with hydrophobic tails oriented toward each other
Nulei of eukaryotic cells are characterized by
a double membrane
Cytoskeleton is to the cell as
bones are to humans and frame is to house.
Compare/Contrast Animal cell and Plant cell
both have rough and smooth ER, a nucleus, ribosomes, and mitochondria. Animal cell has Lysosomes Plant cells have chloroplasts, a cell wall and central vacuole.
Nucleus
contains genetic information that controls the activity of the cell. Brain of the cell.
Facilitated diffusion/active transport
facilitated diffusion and active transport both require membrane transport proteins. However, facilitated diffusion does not require energy and moves substances down a concentration gradient. Active transport requires energy and moves substances against a concentration gradient.
Solutions that cause water to enter cells by osmosis are termed?
hypotonic
Enzyme
is a catalyst. It speeds up a cells reaction by lowering energy of activation.
The compounds in biological membranes that form a barrier to the movement of materials across the membrane are?
lipids
What is active transport?
movement of molecules into or out of a cell against a concentration gradient.
All cells do not posses?
nuclear membrane.
Membrane receptors are proteins that would be synthesized on ribosomes
on the Rough ER
Cell membranes do not
provide the shape and structure to a cell.
Tonicity
refers to the ability of a surrounding solution to cause a cell to gain or loss water.
Nuclear Envelope
regulates the traffic of molecules. controls the flow of molecules between the nucleus and the rest of the cells.
Carbon Dioxide crosses the plasma membrane by simple diffusion What determines the rate which carbon dioxide enters the cell?
the concentration of carbon dioxide on each side of the membrane.
What structure in the membrane causes plasma membranes to resist freezing?
unsaturated fatty acid tails.