AP Bio Unit 2 (Penguins)
10. How are food materials brought in by endocytosis digested?
Vesicles carry materials into the cell and lysosomes release digestive enzymes to break them down.
4. How do large amounts of water pass through the membrane?
Water molecules use osmosis to go from a lower solute concentration to a higher solute concentration. Osmosis is the movement of water across a semipermeable membrane.
4. How does the lysosome aid in intracellular digestion?
When food is absorbed by the cell, the lysosome releases its enzymes to break down macromolecules into usable energy (atp). Main function is to break unwanted macromolecules .
11. What is exocytosis? Identify an example of a material that would require exocytosis.
a process where the cells move materials from within the cell into the extracellular fluid Bulk release of proteins and nutrients
9. Chloroplast What is the structure & function of the chloroplast? How does its structure aid in its function?
a). Structure: Lens-shaped, three compartments Intermembrane space Stroma with DNA and ribosomes Thylakoid space of membranous sacs Function: Converts light energy into chemical energy in photosynthesis. b). Three interconnected spaces allow molecular machinery to convert light energy into chemical energy for photosynthesis.
6. Describe the process of exocytosis.
big particles exiting the cell The vehicle membrane and the plasma membrane come into contact, making the vehicle spill out its contents out of the cell. The vehicle membrane becomes part of the plasma membrane.
4. What is endosymbiotic theory?
organelles were once free living prokaryotes. Mitochondria Chloroplasts
6. Identify two ways the cell completes osmoregulation.
Contractile vacuoles Aquaporins
2. How is a prokaryote compartmentalized?
Different proteins perform different jobs in the cytoplasm in different locations
3. How does the ER aid in intracellular support? (TS)
ER accounts for more than half of eukaryotic cells' membranes Smooth ER stores calcium ions which helps muscle cells contract ER membrane keeps secretory proteins from proteins in cytosol Secretory proteins are moved by vesicles formed from transitional ER Rough ER makes phospholipids in the cell membrane
9. What is endocytosis? Describe three types of endocytosis.
Endocytosis is the process by which cells absorb external material through the formation of vesicles from the cell membrane. The three types are: phagocytosis ("cellular eating"), pinocytosis ("cellular drinking"), and receptor-mediated endocytosis. -Phagocytosis: plasma membrane surrounds a macromolecule environment and buds off to form a food vacuole or phagosome. The newly-formed phagosome then fuses with a lysosome to digest the "food" inside. Pinocytosis:the cell engulfs drops of fluid by pinching in and forming vesicles. Receptor mediated endocytosis: an extremely selective process of importing materials into the cell. This specificity is mediated by receptor proteins
5. Describe the process of endocytosis.
Endocytosis: Molecules entering the cell 3 types: Phagocytosis: Cellular eating (fake feet that engulf food vacuole and bring it in) Pinocytosis: Cellular drinking (Gulps some of the extracellular fluid and brings in solutes) Receptor-mediated endocytosis: Ligand binds to receptor causing a pit, forming vesicle, that goes into cell
6. What is required for active transport?
Energy ATP
5. What is required for active transport?
Energy, usually in the form of ATP.
7. What is the function of an ATPase?
Enzyme that makes ATP by extracting energy from fats, sugars, and other fuel.
4. Identify two examples of active transport.
Exocytosis Movement of large particles for the vacuole out of the cell Endocytosis Movement of larger particles across the cell membrane into the cell
3. How do small amounts of water pass through the membrane?
small amounts of water passes through the membrane through aquaporins channel proteins.
8. Calculate the solute potential of the following sucrose solutions at 27 degrees Celsius. Intracellular-.3M Extracellular-.6M Which way would water flow?
(1) (.3M) (.0821) (300) = 7.389 bars (1) (.6M) (.0821) (300) = 14.778 bars Water would flow out of the cell Water always moves from an area of higher water concentration to one of lower concentration
7. Calculate the solute potential of the following sucrose solutions at 25 degrees Celsius. Intracellular-.5M Extracellular-.2M Which way would water flow?
-12.38 bars -4.95 bars Water would flow into the cell since water flows from an area of high water potential to an area of low water potential
3. What is water potential? How does it explain the direction of water movement?
-Water potential is the potential energy of water in the system when the pressure and temperature are held constant. - The ability of water molecules to flow freely inside a given environment or system can also be measured using water potential. - if the flow is not restricted, water will move from an area of higher water potential to an area that is lower potential
12. What is the function of glycolipids in the plasma membrane?
A glycolipid is covalently attaches a lipid with one or more carbohydrates. They provide energy to the cell and help with cellular recognition
2. What type of surface area to volume ratio is most favorable for cells?
A larger surface area to volume ratio is more favorable. Larger surface area results in more effective processes of the cell due to materials being better able to diffuse materials in a quick manner. A high surface area allows more substances able to enter the cell membrane.
9. Describe the fluid mosaic model.
A model that refers to how the lipid bilayer tends to act more like a liquid than a solid and contains a # of different components Describes the structure of the cell membrane as Dynamic flexible
11. What is the function of glycoproteins in the plasma membrane?
Aids in cell Recognition to determine whether a cell is foreign or familiar and if it should be let through the membrane
2. How does the ribosome demonstrate common ancestry of life?
All forms of life contain ribosomes Similarities between species and life is due to ribosomes
3. How do membrane-bound organelles allow for compartmentalization of the cell and its functions?
Allow for compartmentalization by increasing their surface area. Increased area=More area where reactions occur
6. How does the lysosome aid in apoptosis?
Apoptosis: the process of the death of a cell Lysosomes release enzymes called proteases into the cytosol of the cell that eventually starts the process of apoptosis
8. How does a membrane protein maintain the internal environment of the cell?
By regulating concentration of specific molecule within the cell By controlling what materials/substances enter and leave the cell
6. What is the function of the thylakoid membrane in the chloroplast?
Carries out the light reactions of photosynthesis Helps absorb sunlight Contains all the chlorophyll
5. Golgi Apparatus/Bodies/Complex What is the structure & function of the Golgi? How does its structure aid in its function?
Central intracellular membrane-bound organelle that functions packaging proteins and lipids into vesicles for delivery to targeted destinations have a unique stacked structure
How do charged ions or molecules pass through the membrane?
Charged ions or molecules pass through the membrane through the assistance of transmembrane proteins. They require the assistance of transmembrane proteins since they are unable to pass.
How does the ER provide mechanical support?
Compartmentalization of cell is regulated by ER protein load Protein processing and protein quality control processes
5. How does a cell increase SA without increasing volume?
Compartmentalization, or having small parts inside of a cell that are highly folded.
3. Describe the process of facilitated diffusion.
Facilitated diffusion Movement of larger molecules across the semi-permeable plasma membrane with the help of transport proteins
6. Mitochondria What is the structure & function of the mitochondria? How does its structure aid in its function?
Has a double-membrane system. The inner and outer mitochondrial membranes are separated by an intermembrane space. The mitochondria generates energy to power the cell. The outer membrane contains transport proteins. The inner membrane contains the electron transport chain and ATP synthase.
2. For each type of solution (Hyper, hypo & iso), determine the direction of water flow and the result to the cell.
Hypertonic solution- Water flow will be from cell —> outside Hypotonic solution- Water flow will be outside —> to inside the cell Isotonic solution- Water flow going in & out of the cell will be equal
What does it mean if a solution is hypotonic? Hypertonic? Isotonic?
Hypotonic: low solute concentration and a high amount of free water Hypertonic: higher solute concentration in a lower free water concentration Isotonic: equal amount of water flowing in and out of the cell
5. What is the function of the ER folded membrane?
Important in the Synthesis Folding Modification Transport Of Proteins
5. What are the different types of membrane proteins?
Integral and peripheral proteins Integral: Extend through the whole membrane Peripheral: Only go through part of the protein; not embedded in the lipid bilayer and are loosely bound to the surface of the membrane.
How does the membrane of organelles allow for specific processes to take place? Identify two processes that could not take place without the use of a membrane.
It allows for enzymes to enter the cell and act in specific processes. Photosynthesis and cellular respiration
6. How does the cell wall maintain cell structure?
It is more rigid than the cell membrane, so it will provide more structure and protection. B/c of interlocking protein fibers, more structure provided
8. Vacuoles What is the structure & function of the vacuole? What is the function of the food vacuole? What is the function of the central vacuole? What is the function of the contractile vacuole?
Large vesicles derived from the ER and Golgi apparatus. They transport solutes Food vacuole digests food Central vacuole plays a major role in cell growth and absorbs water Contractile vacuole pump excess water out of the cell
6. What is a concentration gradient?
Measurement of how the concentration changes High to low concentration (across gradient) Low to high concentration (against gradient)
8. How do materials pass through the cell wall?
Molecules use passive diffusion Materials dissolve through the phospholipid bilayer of the membrane Diffuse across it Then dissolve into the aqueous solution on the other side of the membrane.
3. What types of molecules require a vesicle or food vacuole for import? Identify two examples. Why do these require bulk transport?
Neurotransmitters and starches They are too large to fit through the membrane.
3. How is a eukaryote compartmentalized?
Organelles Membrane folding
7. How is a concentration gradient maintained?
Particles moving through transport or channel proteins.
8. Compare and contrast passive and active transport.
Passive transport doesn't need energy to move molecules but active transport does. In active transport, the molecules move against the concentration gradient whereas in passive transport, the molecules move along the concentration gradient.
Describe the process of passive transport.
Passive transport is the transportation of small materials across the membrane. The substances go from high to low concentration until even, also called diffusion. Does NOT require energy
What are the components of the cell membrane?
Phospholipid bilayer Hydrophilic heads Hydrophobic tails Transmembrane proteins Channel Carrier Pump Peripheral Membrane Proteins Integral Membrane proteins Cholesterol Carbohydrate Chains
2. How do each of the cell membrane components function in the cell membrane?
Phospholipids allow small and uncharged particles to move through the membrane. Proteins aid in diffusion and cell recognition. Integral proteins help transport certain materials across the membrane. Cholesterol connects phospholipids together to prevent them from drifting apart too quickly. Glycoproteins are like antibodies. Glycolipids are important for signaling.
9. What composes the cell wall of a plant? Of fungi? A prokaryote?
Plant cellulose Fungi Chitin Prokaryote Peptidoglycan
5. What types of cells have a cell wall?
Plant cells, bacteria, and fungi have a cell wall.
7. How does the polarity of the membrane protein affect its orientation in the membrane?
Polar molecules, such as the membrane protein, are on the extracellular/external sides of the membrane.
5. How do the passage of ions affect the membrane potential?
Positive ions are attracted by the negative side of the membrane and the positive ions are attracted by the negative side of the membrane The more conductive an ion, the more affected the membrane potential will be
4. What is homeostasis?
Process by which a living organism can maintain internal stability while adjusting to changing external conditions.
7. What is the function of the multiple membranes and sacs found in the Golgi?
Processes and tranfers proteins Folds in membrane for larger surface area
2. How does the ER aid in protein synthesis?
Proteins that are produced by ribosomes are attached to the rough ER. Polypeptide chain grows from the attached ribosome and goes into the ER lumen. Carbohydrates attach to the proteins in the lumen, to make glycoproteins. They leave the ER in transport vesicles.
4. What is the relationship between the ribosome and the rough ER?
Ribosomes attached to RER Work together to synthesize, fold, and modify proteins Ribosomes give RER it's rough surface
Identify three similarities and three differences between prokaryotes and eukaryotes.
Similarities Ribosomes Cytoplasm DNA Cell membrane Differences Prokaryotes have a cell wall and eukaryotes do not Eukaryotes have a nucleus and prokaryotes do not Prokaryotes are unicellular and eukaryotes are multi-cellular
2. Identify two examples of passive transport.
Simple Diffusion- small, non charged molecules or lipid soluble molecules pass between the phospholipids to enter or leave the cell. HIGH —> LOW Facilitated Diffusion- selective process of what molecules and ions can pass through the membrane. Moves along the concentration gradient.
7. Compare and contrast simple and facilitated diffusion.
Simple diffusion: Requires no proteins Small substances w/ no charge Substances can go directly through the membrane Both are passive (no ATP) Facilitated diffusion: Requires proteins Substances w/ a charge Channel/carrier protein is used Both are passive (no ATP)
What types of molecules can easily pass through the membrane? Identity two examples. Why are these molecules easily able to pass?
Small and nonpolar or hydrophobic molecules. a). Oxygen and carbon dioxide b). Both are very small particles
2. Describe the process of simple diffusion
Small and uncharged molecules pass through the membrane From areas of high concentration to low concentration No energy required
4. Which cell from #3 is the most efficient? Justify.
Sphere or cylinder have the lower SA:V
3. Calculate the surface area to volume ratios for the following cells Sphere with a radius of 2 Cube with a side length of 3 Rectangular solid with dimensions of 2x3x4 Cylinder with a radius of 2 and a height of 4
Sphere: 50.27:33.51 or 1.5:1 Cube: 54:27 or 2:1 Rectangular solid: 52:24 or 2:1 Cylinder: 75.4:50.27 or 1.5:1
10. What is the function of steroids in the plasma membrane?
Steroids are very important for cell communication. They signal molecules, like hormones. Maintains membrane structure and fluidity.
3. Endoplasmic Reticulum What is the structure & function of the rough ER?: How does its structure aid in its function? What is the structure & function of the smooth ER? How does its structure aid in its function?
Structure: Tube-like & covered in ribosomes. Function: Producing proteins The ribosomes synthesize proteins. Structure: Tube like structure that lacks ribosomes. Function: making hormones and lipids for the cell. The extended surface area of the smooth ER makes it easier to break down and store enzymes.
Ribosomes What is the structure and function of the ribosome? How does the structure aid in its function?
Structure: consists of 2 subunits made up of RNA and protein. Function: site of protein synthesis in cells, where they translate genetic information into proteins. It's structure consists of RNA, which create proteins by translating genetic information.
7. Lysosome What is the structure & function of the lysosome? How does its structure aid in its function?
Structure: sphere shaped sac filled with enzymes Function: break down macromolecules so they are small enough to be used by the cell The enzymes inside are used to break down the macromolecules
2. What types of molecules require a protein to pass through the membrane? Identity two examples. Why does this type of material need help?
Sugars and amino acids Glucose Water They need help because they are either charged or polar and often larger
How does the surface area to volume ratio affect the size of the cell?
The Bigger the cell gets (volume), the less surface area it has for its size. Large cells have large volume and small surface area to volume ratio because volume increases faster than surface area.
7. How does the cell wall protect the cell from hypotonic solutions?
The cell wall is able to withstand pressure in a hypotonic solution Prevents any more water from entering the cell
8. What causes a concentration gradient?
The concentration of solutes goes from area of high to low concentration When there is more solutes inside of the cell than outside When there is more solutes outside of the cell than inside
3. Describe the orientation of the components lipid bilayer.
The lipid bilayer is made from oppositely arranged phospholipids Hydrophilic heads face outside (polar) Hydrophobic tails face inward (nonpolar) Cholesterol within connects phospholipids together Proteins are on the surface or ingrained into the membrane
2. How does the membrane of organelles allow for enzymatic processes to take place?
The membrane of organelles allows each enzyme to have a specific pH and specific function for making lipids, breaking down sugars, etc.
What is passive transport?
The movement of ions and other molecular substances(membrane transport) within the cell without using external energy
4. How does the phospholipid bilayer maintain the internal environment of a cell?
The phospholipid bilayer makes the cell membrane selectively permeable which allows only small nonpolar molecules to diffuse freely, the other molecules have to enter through transport proteins. The bilayer creates a barrier between the cell's surroundings and the cell which allows for a regulated internal environment.
4. Where are plasma membranes found in a cell?
The plasma membrane of an animal cell is the outermost layer The plasma membrane of a plant cell is located just inside the cell wall
5. What is osmoregulation?
The process by which an organism regulates the water balance in its body and maintains the homeostasis of the body
8. How does the sodium potassium ATPase maintain the membrane potential?
The sodium and potassium move against the concentration gradient Helps maintain the gradient of a higher concentration of sodium extracellularly and a higher level of potassium intracellularly.
5. How does the lysosome aid in recycling the cell's organic materials?
They capture and break down malfunctioning proteins Into small pieces that can be reassembled to form new ones.
2. How do large polar molecules pass through the membrane?
Through proteins Channel proteins Facilitated diffusion Active transport Endocytosis Exocytosis Protein pumps
4. What is the function of the inner membrane folding in the mitochondria?
To increase surface area Increases its capacity to synthesize ATP
3. What is active transport?
Transport that moves a cell across the membrane With the use of ATP (Endocytosis and Exocytosis) are Active TRansport
6. Describe the six functions of membrane proteins.
Transportation- aid in allowing large and charged molecules to move across the cell membrane Enzymatic functions - an enzyme that has its active site facing substances outside the lipid bilayer Signal Transduction- a binding site that are characterized by specific shapes that match the shape of a oncoming molecule Cell recognition - helps the body recognize foreign cells that may cause infection Intercellular joining- proteins that connect together to help cells communicate and help transfer materials Attachment - Fibers that help the cell mediate changes
8. How does the vacuole provide turgor pressure?
Turgor pressure: pressure that's exerted by water against the cell wall By regulating the osmotic flow of water Vacuoles store/collect the water within them and regulate the amount present within a cell
4. Describe the process of active transport.
Uses ATP Uses a transport protein like a carrier, channel, or pump Transport proteins take in, or channel molecules through the cell membrane by changing shape and enclosing the molecule, or by creating a hydrophilic channel
7. How does the vacuole assist in storage of macromolecules?
Vacuoles are used for storage. Vacuoles contain hydrolases, which assist in breaking down and storing macromolecules.
