Unit 2 AP BIO EXAM REVIEW

Endo sounds like _________ and can help you remember that cells must use endocytosis to bring large things inside.

enter

Exo sounds like ____________ and can help you remember that cells must use exocytosis to get rid of large things.

exit

Circle the right answer: A plant cell changes the osmolarity of its central vacuole, lowering its water potential. This will cause the vacuole to (gain or loose?) water.

gain

What is selective permeability?

the cell membrane refers to its ability to differentiate between different types of molecules, only allowing some molecules through while blocking others.

Osmosis is the diffusion of:

water

There are three proteins embedded in the membrane. Choose a color for hydrophobic R groups ⬜ and hydrophilic R groups.⬜ Color code the regions of each protein.

Hydrophobic R Groups would embed in the hydrophobic region between phospholipd lipid layers, while the hydrophilic R groups would be sticking out of the membrane, exposed to water.

What property of the phospholipid bilayer prevents the movement of small polar molecules across the membrane?

The hydrophobic portion of the bilayer prevents polar (hydrophilic) molecules from being able to come across the membrane.

Predict the symptoms of a person whose mitochondria have 50% less folding (less surface area) in their inner membrane. Explain your prediction.

The inner membrane holds enzymes involved in the ETC. The more membrane, the more surface area there is for ATP Synthase, which generates ATP. With less membrane, there would be fewer ATP Synthase, so less ATP production. - This person would be very tired all of the time, having very little energy and not able to do physical activities - muscles require a large amount of ATP.- They may also have trouble thinking or concentrating, nerve cells also use a lot of ATP.

What two things do internal membranes (organelles) do for a cell?

Enzymes needed for a specific function of the organelle are isolated in a small space - increases the chance of enzymes colliding with the correct substrate.

Endocytosis and Exocytosis are examples of (passive or active?) transport.

endocytosis: active Exocytosis: active

Draw a root hair cell. Why is its shape important to its function?

The extended protrusion of the cell increases the SA to V ratio,allowing for faster uptake of water and minerals into the cell.

You are studying a cell and notice that Protein A is in the wrong location. What organelles may not be functioning properly? (there are two possibilities)

The golgi complex, or the Rough ER

show your work! What is the surface area-to-volume ratio of... - A cube shape cell, 3 cm x 3 cm - A sphere shape cell that has a 3 cm diameter Which cell is more efficient at eliminating waste and obtaining nutrients from its environment? How do you know?

3 x 3 = 9 cm^3 3 x 3 x 3 = 27 cm^2 1: 3 V = 14 SA= 113 1: 8 cube more effeicent

How does the Fluid Mosaic nature of the cell membrane impact its ability to allow some small molecules pass through freely?

As phospholipids are flowing around, small non-polar molecules are able to diffuse though the membrane more easily. A rigid cell membrane would be less permeable to these molecules.

Name two functions of the cell wall:

Cell walls provide structural support for the cell. They also prevent the cell from taking on too much water via osmosis, providing pressure against the inflow of water, so that the cell does not burst in hypotonic environments.

HOW would the cell lower its water potential?

Increasing the solute potential (amount of solute) inside the vacuole of the plant cell would increase the osmolarity / decrease the water potential of the cell. It could do this by pumping Na+ ions or glucose molecules into the vacuole.

Predict what would happen if the lysosome membrane broke open. Explain your prediction. Do you think cells would do this on purpose? They do! When? __________________

Lysosomes are full of enzymes designed to break down cell parts, if these enzymes were not contained (spilled out into the cell) they could destroy the cell and kill it. During controlled cell death- apoptosis... they do it when they are not functioning correctly

Golgi Complex

Object: packaging factory Explanation: packs and processes protiens Function: a cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell.

Mitochondria

Object: powerhouse Explanation: makes all teh atp Function: Cellular respiration Cellular energy production Calcium homeostasis Cell growth Cell death Oxidative radical regulation Nerve conduction Synthesis of bio-molecules Role in disease Metabolism

Chloroplast

Object: solar power panels Explanation: take light and make energy function: that convert light energy into relatively stable chemical energy via the photosynthetic process. provide diverse metabolic activities for plant cells, including the synthesis of fatty acids, membrane lipids, isoprenoids, tetrapyrroles, starch, and hormones.

Predict the result of doubling the number of thylakoids on glucose production in this chloroplast. Explain your prediction.

With twice the number of thylakoids, there would be double the surface area to conduct light dependent reactions.- This would likely lead to an increase in glucose production (if the enzymes in the Calvin Cycle can keep up).- Additional glucose would allow the plant to grow faster (more cell wall material and more energy) provided that other requirements for growth are met (sufficient nitrogen and phosphorous available).

The Na+/K+ ATPase pump requires ATP (so it is ____________ transport) and is vital to the function of Nerve cells. It maintains an electrochemical gradient so that one side of the membrane is more positive, leaving the other side more negative. The Na+/K+ ATPase proteins are embedded into the axon membrane (long part) of nerve cells. Each one pumps 3 Na out of the cell and 2 K into the cell for each molecule of ATP it uses. Draw three '+' signs outside the cell, and two '+' signs inside the cell.

active

the two organelles believed to have once been free living prokaryotes.

chloroplasts; mitochondria

In your own words, define each term using the meaning of the prefix (in bold) in reference to its solute concentration. - Isotonic - Hypertonic - Hypotonic Define each in terms of osmolarity (high/low/same) Define each in terms of water potential (high/low/same) Draw the shape of a red blood cell after being placed into each type of solution. Draw arrows showing the movement of water across the membrane. Label the areas high water potential and low water potential.

isotonic: equal (same) (healthy blood cell) hypertonic: overstimulated (more solute outside = water goes out) (shrunk blood cell) hypotonic: under (more solute inside = water come in) (blood cell swells --> pop)

What is the big difference between passive and active transport (as indicated by their names)?

passive uses NO energy, while Active DOES USE energy

Is this an example of passive or active transport?

passive: diffusion (osmosis) Active: proton potassium pump

What is the role of an Aquaporin protein?

selectively conduct water molecules in and out of the cell, while preventing the passage of ions and other solutes. Also known as water channels, aquaporins are integral membrane pore proteins.

In your own words, what is the Endosymbiotic theory: Describe what is believed to have happened to form the first Eukaryotic cell.

the theory states that the common ancestor of all eukaryotic cells was once a prokaryotic cell, that engulfed another prokaryote cell, These engulfed cells were not destroyed, but rather began living in and depending on the host cell. The endosymbionts that were able to perform aerobic cellular respiration became mitochondria, while those that could do photosynthesis were the ancestors of the chloroplast.

How would these now-organelles have lived on their own? (What did they do to acquire energy for themselves?)

they have ribsomes/ ability to convert light into energy they are also membrane bound organelles

You have not watered your plant in a few days. It is droopy and floppy. What has happened on a cellular level (be specific to a particular organelle)? What will happen if you water it? Explain.

- The central vacuole of the plant cells is designed to fill with water and push against cell walls, holding the plant upright.- When dehydrated, the vacuoles shrink, and are no longer pushing against cell walls, so they sag, leading to drooping plants.- When the plant is watered, vacuoles will fill again, push against cell walls, and the plant will stand upright again.

Which cell part(s) are found in both Eukaryote and Prokaryote cells? What does this suggest about the history of life?

- plasma membrane, ribosomes, cytoplasm, and DNA This suggest that eukaryotes evolved form prokarote cells because they have similar functions and organelles The last universal common ancestor to all life likely had ribosomes and a cell membrane, which it then passed down to all of its descendants, eventually evolving into all domains of life.

What type of molecule passes via: Simple diffusion? _________ Facilitated diffusion? _______ Active transport pump? ________

- small non-polar, lipid hormones, oxygen, carbon dioxide - Large and/or polar - glucose, proteins, water, ions -large and polar, goes aginst gradient na/K/ hormones

Calculate the water potential of a 0.3 molar glucose solution in an open beaker at 25 degrees celsius. Show your work.

1.5 MOL

If you put a protist into the same three environments, which environment would you expect its contractile vacuole to be most active? Explain your answer.

A protist's contractile vacuole would be most active in the hypotonic environment. In low levels of solute (areas of high water potential) water will be constantly entering the cell through osmosis. The protist will combat this by squeezing water out via its contractile vacuole. In hypertonic solutions, the protist would have another problem - losing too much water to its environment.

The fluid mosaic model states that the parts of the cell membrane continually move past one another. If the diagram above were a photo of a living cell membrane, draw a representation of that same cell if you took another photo 20 minutes later. Add the same three proteins to the diagram on the left.

Any drawing with the proteins in different positions- showing that the proteins have moved.

Which of these beakers has the lowest solute potential? A) 1 molar solution of glucose B) 0.5 molar solution of glucose C) 1 molar solution of NaCl D) 0.5 molar solution of NaCl

C

WHY would a cell want to lower the water potential of its vacuole?

If the cell needs to take more water into itself from the soil, it can do so by lowering its water potential. The greater the contrast between the soil and the cell, the faster water will enter. Maybe the soil is more dry than usual, or the plant is located in a more hypertonic environment.

TOPIC 2.4 Plasma Membranes

ENDURING UNDERSTANDING: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. LEARNING OBJECTIVE ENE-2.A Describe the roles of each of the components of the cell membrane in maintaining the internal environment of the cell. ESSENTIAL KNOWLEDGE ENE-2.A.1 Phospholipids have both hydrophilic and hydrophobic regions. The hydrophilic phosphate regions of the phospholipids are oriented toward the aqueous external or internal environments, while the hydrophobic fatty acid regions face each other within the interior of the membrane. ENE-2.A.2 Embedded proteins can be hydrophilic, with charged and polar side groups, or hydrophobic, with nonpolar side groups. LEARNING OBJECTIVE ENE-2.B Describe the Fluid Mosaic Model of cell membranes. ESSENTIAL KNOWLEDGE ENE-2.B.1 Cell membranes consist of a structural framework of phospholipid molecules that is embedded with proteins, steroids (such as cholesterol in eukaryotes), glycoproteins, and glycolipids that can flow around the surface of the cell within the membrane.

TOPIC 2.6 Membrane Transport

ENDURING UNDERSTANDING: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. LEARNING OBJECTIVE ENE-2.E Describe the mechanisms that organisms use to maintain solute and water balance. ESSENTIAL KNOWLEDGE ENE-2.E.1 Passive transport is the net movement of molecules from high concentration to low concentration without the direct input of metabolic energy. ENE-2.E.2 Passive transport plays a primary role in the import of materials and the export of wastes. ENE-2.E.3 Active transport requires the direct input of energy to move molecules from regions of low concentration to regions of high concentration. LEARNING OBJECTIVE ENE-2.F Describe the mechanisms that organisms use to transport large molecules across the plasma membrane. ESSENTIAL KNOWLEDGE ENE-2.F.1 The selective permeability of membranes allows for the formation of concentration gradients of solutes across the membrane. ENE-2.F.2 The processes of endocytosis and exocytosis require energy to move large molecules into and out of cells— a. In exocytosis, internal vesicles fuse with the plasma membrane and secrete large macromolecules out of the cell. b. In endocytosis, the cell takes in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane.

TOPIC 2.7 Facilitated Diffusion

ENDURING UNDERSTANDING: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. LEARNING OBJECTIVE ENE-2.G Explain how the structure of a molecule affects its ability to pass through the plasma membrane. ESSENTIAL KNOWLEDGE ENE-2.G.1 Membrane proteins are required for facilitated diffusion of charged and large polar molecules through a membrane— a. Large quantities of water pass through aquaporins. b. Charged ions, including Na+ and K+, require channel proteins to move through the membrane. c. Membranes may become polarized by movement of ions across the membrane. ENE-2.G.2 Membrane proteins are necessary for active transport. ENE-2.G.3 Metabolic energy (such as from ATP) is required for active transport of molecules and/ or ions across the membrane and to establish and maintain concentration gradients. ENE-2.G.4 The Na+/K+ ATPase contributes to the maintenance of the membrane potential.

TOPIC 2.8 Tonicity and Osmoregulation

ENDURING UNDERSTANDING: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. LEARNING OBJECTIVE ENE-2.H Explain how concentration gradients affect the movement of molecules across membranes. ESSENTIAL KNOWLEDGE ENE-2.H.1 External environments can be hypotonic, hypertonic or isotonic to internal environments of cells— a. Water moves by osmosis from areas of high water potential/low osmolarity/ low solute concentration to areas of low water potential/high osmolarity/high solute concentration. ** See the equations for Water Potential your Formula Sheet ILLUSTRATIVE EXAMPLES § Contractile vacuole in protists § Central vacuoles in plant cells LEARNING OBJECTIVE ENE-2.I Explain how osmoregulatory mechanisms contribute to the health and survival of organisms. ESSENTIAL KNOWLEDGE ENE-2.I.1 Growth and homeostasis are maintained by the constant movement of molecules across membranes. ENE-2.I.2 Osmoregulation maintains water balance and allows organisms to control their internal solute composition/water potential. **See the equation for Solute Potential on your formula sheet

TOPIC 2.9 Mechanisms of Transport

ENDURING UNDERSTANDING: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. LEARNING OBJECTIVE ENE-2.J Describe the processes that allow ions and other molecules to move across membranes. ESSENTIAL KNOWLEDGE ENE-2.J.1 A variety of processes allow for the movement of ions and other molecules across membranes, including passive and active transport, endocytosis and exocytosis.

TOPIC 2.10 Compartmentalization

ENDURING UNDERSTANDING: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. LEARNING OBJECTIVE ENE-2.K Describe the membrane-bound structures of the eukaryotic cell. ESSENTIAL KNOWLEDGE ENE-2.K.1 Membranes and membrane-bound organelles in eukaryotic cells compartmentalize intracellular metabolic processes and specific enzymatic reactions. LEARNING OBJECTIVE ENE-2.L Explain how internal membranes and membrane-bound organelles contribute to compartmentalization of eukaryotic cell functions. ESSENTIAL KNOWLEDGE ENE-2.L.1 Internal membranes facilitate cellular processes by minimizing competing interactions and by increasing surface areas where reactions can occur.

TOPIC 2.5 Membrane Permeability

ENDURING UNDERSTANDING: Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. LEARNING OBJECTIVE ENE-2.C Explain how the structure of biological membranes influences selective permeability. ESSENTIAL KNOWLEDGE ENE-2.C.1 The structure of cell membranes results in selective permeability. ENE-2.C.2 Cell membranes separate the internal environment of the cell from the external environment. ENE-2.C.3 Selective permeability is a direct consequence of membrane structure, as described by the fluid mosaic model. ENE-2.C.4 Small nonpolar molecules, including N2, O2, and CO2 , freely pass across the membrane. Hydrophilic substances, such as large polar molecules and ions, move across the membrane through embedded channel and transport proteins. ENE-2.C.5 Polar uncharged molecules, including H2O, pass through the membrane in small amounts. LEARNING OBJECTIVE ENE-2.D Describe the role of the cell wall in maintaining cell structure and function. ESSENTIAL KNOWLEDGE ENE-2.D.1 Cell walls provide a structural boundary, as well as a permeability barrier for some substances to the internal environments. ENE-2.D.2 Cell walls of plants, prokaryotes, and fungi are composed of complex carbohydrates.

TOPIC 2.11 Origins of Cell Compartmentalization

ENDURING UNDERSTANDING: Evolution is characterized by a change in the genetic makeup of a population over time and is supported by multiple lines of evidence. LEARNING OBJECTIVE EVO-1.A Describe similarities and/or differences in compartmentalization between prokaryotic and eukaryotic cells. ESSENTIAL KNOWLEDGE EVO-1.A.1 Membrane-bound organelles evolved from once free-living prokaryotic cells via endosymbiosis. EVO-1.A.2 Prokaryotes generally lack internal membrane-bound organelles but have internal regions with specialized structures and functions. EVO-1.A.3 Eukaryotic cells maintain internal membranes that partition the cell into specialized regions. LEARNING OBJECTIVE EVO-1.B Describe the relationship between the functions of endosymbiotic organelles and their free-living ancestral counterparts. ESSENTIAL KNOWLEDGE EVO-1.B.1 Membrane-bound organelles evolved from previously free-living prokaryotic cells via endosymbiosis

TOPIC 2.1 Cell Structure: Subcellular Components

ENDURING UNDERSTANDING: Living systems are organized in a hierarchy of structural levels that interact. LEARNING OBJECTIVE SYI-1.D Describe the structure and/ or function of subcellular components and organelles. ESSENTIAL KNOWLEDGE SYI-1.D.1 Ribosomes comprise ribosomal RNA (rRNA) and protein. Ribosomes synthesize protein according to mRNA sequence. SYI-1.D.2 Ribosomes are found in all forms of life, reflecting the common ancestry of all known life. SYI-1.D.3 Endoplasmic reticulum (ER) occurs in two forms—smooth and rough. Rough ER is associated with membrane-bound ribosomes— a. Rough ER compartmentalizes the cell. b. Smooth ER functions include detoxification and lipid synthesis. X Specific functions of the smooth ER in specialized cells are beyond the scope of the AP Exam SYI-1.D.4 The Golgi complex is a membrane-bound structure that consists of a series of flattened membrane sacs— a. Functions of the Golgi include the correct folding and chemical modification of newly synthesized proteins and packaging for protein trafficking. ILLUSTRATIVE EXAMPLE § Glycosylation and other chemical modifications of proteins that take place within the Golgi and determine protein function or targeting X The role of the Golgi in the synthesis of specific phospholipids and the packaging of specific enzymes for lysosomes, peroxisomes, and secretory vesicles are beyond the scope of the AP Exam. b. Mitochondria have a double membrane. The outer membrane is smooth but the inner membrane is highly convoluted, forming folds c. Lysosomes are membrane-enclosed sacs that contain hydrolytic enzymes. d. A vacuole is a membrane-bound sac that plays many and differing roles. In plants, a specialized large vacuole serves multiple functions. e. Chloroplasts are specialized organelles that are found in photosynthetic algae and plants. Chloroplasts have a double outer membrane.

TOPIC 2.2 Cell Structure and Function

ENDURING UNDERSTANDING: Living systems are organized in a hierarchy of structural levels that interact. LEARNING OBJECTIVE SYI-1.E Explain how subcellular components and organelles contribute to the function of the cell. ESSENTIAL KNOWLEDGE SYI-1.E.1 Organelles and subcellular structures, and the interactions among them, support cellular function— a. Endoplasmic reticulum provides mechanical support, carries out protein synthesis on membrane-bound ribosomes, and plays a role in intracellular transport. b. Mitochondrial double membrane provides compartments for different metabolic reactions. c. Lysosomes contain hydrolytic enzymes, which are important in intracellular digestion, the recycling of a cell's organic materials, and programmed cell death (apoptosis). d. Vacuoles have many roles, including storage and release of macromolecules and cellular waste products. In plants, it aids in retention of water for turgor pressure. LEARNING OBJECTIVE SYI-1.F Describe the structural features of a cell that allow organisms to capture, store, and use energy. ESSENTIAL KNOWLEDGE SYI-1.F.1 The folding of the inner membrane increases the surface area, which allows for more ATP to be synthesized. SYI-1.F.2 Within the chloroplast are thylakoids and the stroma. SYI-1.F.3 The thylakoids are organized in stacks, called grana. SYI-1.F.4 Membranes contain chlorophyll pigments and electron transport proteins that comprise the photosystems. SYI-1.F.5 The light-dependent reactions of photosynthesis occur in the grana. SYI-1.F.6 The stroma is the fluid within the inner chloroplast membrane and outside of the thylakoid. SYI-1.F.7 The carbon fixation (Calvin-Benson cycle) reactions of photosynthesis occur in the stroma. SYI-1.F.8 The Krebs cycle (citric acid cycle) reactions occur in the matrix of the mitochondria. SYI-1.F.9 Electron transport and ATP synthesis occur on the inner mitochondrial membrane

TOPIC 2.3 Cell Size

ENDURING UNDERSTANDING: The highly complex organization of living systems requires constant input of energy and the exchange of macromolecules. LEARNING OBJECTIVE ENE-1.B Explain the effect of surface area-to-volume ratios on the exchange of materials between cells or organisms and the environment. ESSENTIAL KNOWLEDGE ENE-1.B.1 Surface area-to-volume ratios affect the ability of a biological system to obtain necessary resources, eliminate waste products, acquire or dissipate thermal energy, and otherwise exchange chemicals and energy with the environment. **See formulas for surface area and volume in your Formula Sheet ENE-1.B.2 The surface area of the plasma membrane must be large enough to adequately exchange materials— a. These limitations can restrict cell size and shape. Smaller cells typically have a higher surface area-to-volume ratio and more efficient exchange of materials with the environment. b. As cells increase in volume, the relative surface area decreases and the demand for internal resources increases. c. More complex cellular structures (e.g., membrane folds) are necessary to adequately exchange materials with the environment. d. As organisms increase in size, their surface area-to-volume ratio decreases, affecting properties like rate of heat exchange with the environment. ILLUSTRATIVE EXAMPLES SA/V Ratios and Exchange § Root hair cells § Guard cells § Gut epithelial cells LEARNING OBJECTIVE ENE-1.C Explain how specialized structures and strategies are used for the efficient exchange of molecules to the environment. ESSENTIAL KNOWLEDGE ENE-1.C.1 Organisms have evolved highly efficient strategies to obtain nutrients and eliminate wastes. Cells and organisms use specialized exchange surfaces to obtain and release molecules from or into the surrounding environment. ILLUSTRATIVE EXAMPLES § Vacuoles § Cilia § Stomata

Which molecules can pass freely through the plasma membrane? Why? Which molecules must move through a protein channel? Why? Glucose Na+ ions Water Large protein hormone Small lipid hormone (steroid) Oxygen

Glucose: Requires a protein channel, it is too large to cross the membrane Na+ ions: Requires a protein channel, while it is small, Na+ is acharged ion, so it will not be able to cross the hydrophobic barrier Water: Requires a protein channel (aquaporin) because water is polar (though some water will still seep in through the lipid bilayer). Large protein Hormone: Requires a protein channel because it is too large to move across the membrane. Small lipid: hormone (steroid): Can move freely into/out of the cell. Being small, and a lipid, it can pass through the hydophobic portion of the lipid bilayer. Oxygen: Can move freely across the membrane, both small and non-polar

On the Mitochondrion above, label the location of the Krebs Cycle and the location of the Electron Transport Chain.

KREBS: in mitichondria --> folded inner membrane (matrix) ETC: in mitichondria--> protiens invloved in teh ETC are embedded on folded inner memebrane (intermembrane space)

On the chloroplast, label the stroma, thylakoid disks, and grana. Label the location of the light dependant reactions and of Carbon Fixation.

Light dependent: Grana Carban Fixation: stroma

If the loaf were a living organism, why would it be better for that organism to be composed of many small pieces rather than one large piece?

Living organisms must be able to quickly take in substances from the environment and get rid of waste. The smaller the organism, the higher its surface area to volume ratio is, allowing it to perform transport into and out of the cell more quickly.

Draw a gut epithelial cell. Why its shape important to its function?

Microvilli - extensions of the cell membrane -increase the surface area, allowing for quicker absorption of nutrients from the small intestine to be absorbed into the blood stream.

List three pieces of evidence that supports the Endosymbiotic theory.

Mitochondria and Chloroplasts contain their own rings of DNA (plasmids), they divide independently of the cell, they contain ribosomes which have similar structure to prokaryotes, they have a double membrane (suggesting the outer membrane was part of the host membrane as it engulfed the smaller prokaryote), and they are about the same size as prokaryotes

Ribosomes

Object: fast food place Explanation: b/e it pumps out protiens Function: Ribosomes are the sites in a cell in which protein synthesis takes place. ... Within the ribosome, the rRNA molecules direct the catalytic steps of protein synthesis — the stitching together of amino acids to make a protein molecule.

Rough ER

Object: food factorie Explanation: pumps out food and ships it off Function: primarily concerned with the synthesis, folding and modification of proteins, especially those that need to be delivered to different organelles within the cell, or secreted from the cell. The rough ER is also involved in the response of the cell to unfolded proteins and plays a role in the induction of apoptosis, due to its close interaction with mitochondria.

Smooth ER

Object: the halls of a factory through which information passes. Explanation: The information in the case of a cell is messenger RNA. function: It synthesizes lipids, phospholipids as in plasma membranes, and steroids. it also is used to pass mRNA. It is also a storage organelle. It is important in the creation and storage of lipids and steroids.

Lysosomes

Object: trash can Explanation: gets ride of waste and breaks down material function: contains digestive enzymes. Lysosomes are involved with various cell processes. They break down excess or worn-out cell parts. They may be used to destroy invading viruses and bacteria.

Vacuole

Object: water tank Explanation: holds waste and water function: In animal cells, vacuoles are generally small and help sequester waste products. In plant cells, vacuoles help maintain water balance. Sometimes a single vacuole can take up most of the interior space of the plant cell.

What kinds of cells have cell walls (three types), and what type of carbohydrate material is each cell wall made of?

Plants-cellulose Fungus- chitin Bacteria-peptidoglycan

Complete the chart for each type of cell. This cell type... ...would do a lot of (endo or exocytosis?)... ...to move _____?_______ across the membrane. Plasma B Cell Neuron Macrophage cell Palisade Plant cell

Plasma B Cell: would do a lot of: exocytosis to move antibodies across the membrane. Neuron - would do a lot of exocytosis to move neurotransmitters across the membrane. Macrophage cell would do a lot of endocytosis to move bacteria across the membrane. Palisade Plant cell would do a lot of endocytosis to move glucose across the cell membrane.

List the major differences between Prokaryote and Eukaryote cells.

Prokaryotes: (bacteria/archaea, no nucleus/organelles, rely on infolding of their outer membranes to perform tasks such as PS and aerobic CR, circle DNA, smaller)

Protists with cell walls do not have (or need) contractile vacuoles - why not?

The cell wall acts as a physical constraint against taking in too much water. The cell can only swell so much, before the cell wall pushes back and prevents any further swelling. It is kind of like trying to blow up a balloon inside a small cardboard box - you will not be able to blow it up to the point where it pops because the box will prevent the balloon from expanding too much.

Picture a hot potato. Now picture a GIANT HOT POTATO! Which potato will cool off faster? Why? Explain in terms of SA/V ratio. The hot potato is now a mouse, and the GIANT hot potato is now an elephant. Which organism must have a higher metabolic rate (burn more energy) to maintain its body heat? Explain why.

The large potato would take a lot longer to cool off, as it has a smaller surface area to volume ratio. The best way to cool a hot potato is to open it up and cut it into pieces, increasing the surface area exposed to cool air. The elephant has a low SA to V ratio, so it holds onto heat, meaning it needs to spend less energy heating itself. - The mouse, being small, has a high SA to V ratio and looses heat to the environment at a higher rate - so it must burn more energy per unit mass in order to maintain its body temp.

Draw a red blood cell. Why is the shape of the RBC important to its function?

Vacuoles store food and nutrients, as well as wastes,winch can quickly diffuse into or out of the cytoplasm either to the environment,or to the vacuole.

Draw a very simple plant cell with a large central vacuole. How does a vacuole increase the rate that plant cells can exchange materials with its environment?

Vacuoles store food and nutrients, as well as wastes,winch can quickly diffuse into or out of the cytoplasm either to the environment,or to the vacuole.

you have 2 loafs of bread but one is whole and the other is cute into slices. mentally drop each loaf into water. Which loaf will become saturated first? Explain why.

cutting the loaf of bread in slices increases the surface area exposed to water. The higher the surface area to volume ration of the sliced breads will cause it to become fully saturated sooner than the uncut loaf.

Label the hydrophobic and hydrophilic parts of one phospholipid.

head: hydropilic tail: hydrophobic

What happens across the inner membrane of the mitochondria? Why is the inner membrane so highly folded (what is the advantage)?

inner membrane is highly folded with folds called cristae. inside of inner mitochondrial membrane is called matrix. this has ribsome and makes energy --> more folds = more surface area = more energy

Circle the right word: The Na+/K+ ATPase proteins maintain a membrane potential so that the (inside, outside) has a more negative charge compared to the (inside, outside) of the cell.

outside --> inside

Would movement through this protein be an example of what type of transport? (passive or active? Which type specifically?)

passive

Predict what would happen if a mutation caused one of the hydrophobic R groups to be switched with a hydrophilic R group. Explain your thoughts:

the membrane would not be shaped the same because the hydropobic protien would try to bend way form water causing it to not form right

In your own words, why is compartmentalization of functions helpful to a cell? Use the rooms in your own home as an analogy. Also include at least one specific organelle example.

this makes different organelles specialized in different functions allowing them to work effectively with each other allowing more complex animals.