Unit 2 - Cells

What does passive transport play a role in?

Import of materials and the export of wastes

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

active

exocytosis and endocytosis

active transport, energy IS used, proteins are not used, vesicles ARE used

Peripheral protein

adhere to the membrane - found on surface of cytoplasmic or extracellular side

Where are chloroplasts found?

algae and plants

Exocytosis:

a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.

What do cell walls provide?

a structural boundary, as well as a permeability barrier for some substances to the internal environments

Carrier proteins

a transport protein that changes shape and transports materials across the membrane. Use in active transport (sodium-potassium pump) and facilitated diffusion (glucose transporter)

Channel proteins

a transport protein that moves hydrophilic materials - a channel is opened and materials flow into or out of the cell. Passive transport. Inner part of channel is hydrophilic but the part of the channel protein that touches the phospholipid tails is hydrophobic.

What are the lysosomes?

contain enzymes that break down faulty cell parts and invaders. often described as the recycling centers of the cell

A plant cell changes the osmolarity of its central vacuole, lowering its water potential. This will cause the vacuole to __________ water

gain

Integral protein

protein embedded throughout the lipid bilayer. Areas exposed to the extracellular environment and cytoplasm are hydrophilic while areas touching the nonpolar tails are hydrophobic

What is the golgi complex?

proteins come here to be modified and tagged to be sent to other parts of the cell, or to leave the cell

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

provide surface area for reactions to happen (ex. high surface area of the Rough ER for greater number of ribosomes) and they create compartmentalized micro-environments for specialized functions (ex. lysosome)

What forms a ribosome?

rRNA and proteins

Large protein hormone and cell membrane

requires a protein channel to move across membrane because it is too large to move across the membrane

Which cell parts are found in both eukaryote and prokaryote cells?

ribosomes and the cell membrane

What does the structure of cell membranes result in?

selective permeability

What is the chloroplast?

site of photosynthesis in autotrophs. Light energy is used to create glucose, converting radiant energy into chemical energy

Simple diffusion molecules that can pass

small non-polar, lipid hormones, oxygen, carbon dioxide

Active transport pump molecules that can pass?

specific example: Na/K pump in neurons

What are granas?

stacks of thylakoids

Cholesterol

steroid this is very important for maintaining the fluidity of the plasma membrane. Prevents membrane from becoming too rigid or too fluid.

Where does the Calvin Cycle (Carbon fixation) take place?

stroma

Describe the cell membrane:

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.

What is selective permeability?

the cell has properties that allow it to allow only some molecules to pass across the membrane, allowing it to help maintain homeostasis within the cell

What happens in endocytosis?

the cell takes in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane.

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

you are studying a cell and notice that protein A is in the wrong location. what organelles may not be functioning properly?

the golgi complex or the Rough ER

Why does the surface area of the plasma membrane have to be large enough?

To exchange materials

Why are more complex collar structures nessesary?

To exchange materials with the environment

Diffusion

- passive transport - no energy use - does not use proteins - does not use vesicles - high to low concentration (with gradient)

Osmosis

- passive transport - no energy use - does not use proteins - does not use vesicles - high to low concentration (with gradient)

Facilitated diffusion

- passive transport - no energy use - proteins ARE used - does not use vesicles - high to low concentration (with gradient)

Active transport

- active transport - energy IS used - proteins ARE used - does not use vesicles - low to high concentration (against gradient)

If you put a protist in the same three environments, which environment would you expect its contractile vacuole to be most active

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

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

Pinocytosis

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes

What are membrane proteins nesseary for

Active transport

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

Active transport requires the cell to use ATP to move molecules across the membrane, while passive transport does not require ATP, molecules move via diffusion

What is the sodium potassium pump? (Na+/K+)

An electrogenic pump in which ATP is used to keep Na+ and K+ in disequilibrium and maintain membrane potential. This allows for a neuron to generate an impulse.

What are the ribosomes?

Are the location of protein synthesis, RNA is read and the code is used to form a polypeptide chain.

How does the fluid mosaic nature of the cell membrane impact is ability to allow some small molecules to pass through freely?

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

What is the cristae?

folds in the inner membrane of mitochondria

How are growth and homeostasis maintained?

By the constant movement of molecules across the membrane

Oxygen and cell membrane

Can move freely across the membrane because it is both small and non-polar

Small lipid hormone (steroid) and cell membrane

Can move freely into/out of cell across membrane - being small, and a lipid, it can pass through the hydrophobic portion of the lipid bilayer

What is cytolysis?

Cell burst from water intake. Plant cells do not experience this.

For each cellular process below, explain the internal region that prokaryotes use since they do not have a specific organelle. -Cellular respiration -Photosynthesis -DNA replication -Transcription -Translation

Cellular respiration - occurs the cell membrane Photosynthesis - photosynthetic bacteria have thylakoid membranes DNA Replication - the nucleoid region (DNA in plasmid ring) Transcription- the nucleoid region (translation can begin before transcription is complete Translation - also on ribosomes

What do charged ions require to move through the membrane?

Channel membranes

Why is compartmentalization of functions helpful to a cell? use the rooms in your own home as an analogy. Also include one specific organelle example

Compartmentalization keeps all the ingredients and enzymes necessary for specific reactions in a concentrated space so they do not diffuse away from one another. Like your kitchen, you need kitchen supplies and food ingredients in the same room in order to make a meal. Compartmentalization also separates competing reactions, or prevents damage to other components (enzymes located in lysosomes can not destroy other organelles). Similar to the mess left in the garage of a house - you want to keep the dirty tools, oil, outdoor items out of the other rooms of the house

What are cell walls comprised of?

Complex carbohydrates

What is the function of the Golgi complex?

Correct folding and chemical modification of newly synthesized proteins and packaging for protein trafficking

If a loaf of bread is sliced up and the other one is not and are both dropped in water, which will become saturated first?

Cutting the loaf of bread into slices increases the surface area exposed to the water. The higher surface area to volume ratio of the sliced bread will cause it to become fully saturated sooner than the un-cut loaf

Addition of solute to a solution causes a:

Decrease in water potential

What is the Smooth ER associated with?

Detoxification and lipid synthesis

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

Electron transport chain enzymes located here (final step in cellular respiration) - more surface area can hold more enzymes, allowing for higher production of ATP molecules

What is the Endosymbiotic theory: describe what is believed to have happened to form the first Eukaryotic cell

Endo-sym-biot means inside-together-life. 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

What process requires energy to move large molecules into and out of cells?

Exocytosis and endocytosis

Which of the following claims is scientifically accurate and consistent with an observation that a decrease in lysosome production within a cell leads to a decline in mitochondrial activity?

Fewer lysosomes will be available to break down macromolecules to provide the necessary nutrients for cellular respiration.

Function of centrioles

Form the spindle during cell division, only in animal cells

Describe a solution with high osmolarity.

High solute/low water

What do cell membranes seperate?

Internal and external environment

Where would the hydrophobic R groups go in a phospholipid bilayer?

Hydrophobic R groups would embed in the hydrophobic region between phospholipid layers, while the hydrophilic R groups would be sticking out, of the membrane expose to water

Describe how animal cells react in hypotonic, hypertonic and isotonic solutions.

Hypotonic - cell swells, cytolysisHypertonic - cell shrinks, plasmolysisIsotonic - prefered, cell/solution at equilibrium

Describe how plant cells react in hypotonic, hypertonic and isotonic solutions.

Hypotonic - prefered environment, large,central vacuole filled with water, presses cytoplasm into plasma membrane and cell wall. Can maintain turgor pressureHypertonic - cell looses water, plasma membrane can detach from cell wall (but the cell does not shrink)Isotonic - plant wilts, lose of turgor pressure

Why is it important for cells to have a large surface area to volume ratio?

In order to allow for adequate exchange of materials (nutrients, water, waste) to keep the cell alive

What is the stroma?

Is the fluid within the inner chloroplast membrane and outside of the thylakoid

How does exocytosis work?

Large materials such as proteins leave the cell. A vesicle surrounds the material and transports it to the plasma membrane (after proteins leave the golgi bodies). The vesicle fuses with the plasma membrane and the materials are pushed out of the cell.

How does endocytosis work?

Large materials transported into the cell/press into the cell membrane/phospholipids pinch off and surround the material and transport it into the cell.Phagocytosis - cell eating - solid materials/Pinocytosis - materials dissolved in liquid first.

What molecules need channel and transport proteins to fit through?

Large polar molecules and ions

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

Living organisms must be able to quickly take in substances from the environment (oxygen, water, nutrients) and get rid of waste (nitrogenous waste, carbon dioxide). The smaller the organism, the higher its surface area to volume ratio is, allowing it to preform transport into and out of the cell more quickly

Describe a solution with low osmolarity

Low solute/high water

Predict what would happen if the lysosomes membrane broke open. Explain you prediction:

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

Describe the structure of the Rough ER

Membrane bound organelle formed of folded membranes in order to greatly increase surface area and allow for multiple ribosomes to bind to the Rough ER.

Describe the structure of golgi bodies

Membrane bound structure that is formed of flattened sacs (cisternae) that greatly increase surface area, contains enzymes that modify molecules

Function/structure of lysosomes?

Membrane sacs filled with hydrolytic enzymes - intracellular digestion - food vacuoles, watse, apoptosis (programmed cell death)Produced by the golgi bodies

What is the rough ER associated with?

Membrane-bound ribosomes and compartmentalizes the cell

Changing the shape or morphology of the mitochondrial inner membrane can change the efficiency of mitochondrial function.Which of the following outcomes will most likely result from a change in the shape of the mitochondrial inner membrane from a highly folded surface to a smooth, flat surface?

Mitochondria will become less efficient because the surface area of the inner mitochondrial membranes will decrease.Correct. The change to the inner mitochondrial membrane will result in a decrease in the membrane's surface area, which will reduce the efficiency of mitochondrial function because there will be less surface area for reactions to occur.

What are contractile vacuoles?

Organelle found in some single celled eukaryotes such as paramecium. Pumps out excess water because they live in a hypotonic environment (freshwater)

Membrane-bound organelles have been an important component in the evolution of complex, multicellular organisms. Which of the following best summarizes an advantage of eukaryotic cells having internal membranes?

Organelles isolate specific reactions, increasing metabolic efficiency.

What is the benefit of having membrane bound organelles?

Organelles provide compartmentalization of cellular processes. This prevents competing reactions from interfering and increases surface area allows for the organelle to be more efficient (ex. More ribosomes on Rough ER due to more surface area = more proteins produced)

Na+ ions and cell membrane

Requires a protein channel to move across membrane, while is is small, Na+ is a charged ion so it will not be able to cross the hydrophobic barrier of the membrane

Define each component of the plasma membrane: Phospholipid Glycoprotein Glycolipid -

Phospholipid - polar head, fatty acid, nonpolar tails. Polar heads exposed to extracellular environment or cytoplasm. Responsible for semi-permeable nature of plasma membrane.Glycoprotein- carbohydrate attached to a protein (blood type) Glycolipid- carbohydrate attached to a lipid

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

Plant cell walls: made of glucoseFungus cell walls: made of chitinBacterial cell walls: made of peptidoglycan

What molecules can pass through in small amounts?

Polar uncharged molecules including H2O

What did membrane-bound organelles evolve from?

Previously free-living prokaryotic cells via emdosymbisosis

Some functions of the cell wall:

Provide structural support for the cell and prevents the cell from taking in too much water via osmosis, providing pressure against the inflow of water, so that the cell does not burst in hypotonic environments

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

RBCs are flattened, with an impression in the middle. This increases the surface area of the cell, allowing for more rapid absorption of oxygen into the cell, and release of oxygen as it move through the body tissues

What comprises a Ribosome?

RNA and a protein

Water and cell membrane

Requires a protein channel to move across membrane (aquaporin) because water is polar (though some water will still seep in through the lipid bilayer)

What does Glucose and cell membrane need to move?

Requires a protein channel to move across membrane - it is too large to cross the membrane

You are told that an unidentified cell contains a single, circular DNA molecule but no nucleus. Which of the following would you also expect the cell to possess?

Ribosomes

What happens to proteins formed in the rough ER vs. in the cytoplasm?

Rough ER-site specific proteins leave the cell or embedded in cell membrane Cytoplasm - proteins remain the cell

What molecules can pass freely through the membrane?

Small non-polar molecules

What two forms do the endoplasmic reticulum come in?

Smooth and rough

What is the Rough ER?

Studded with ribosomes, proteins are made here that are then transported to other parts of the cell. Rough ER also plays a role in intracellular transport.

What do ribosomes do?

Synthesize proteins according to mRNA sequence

What reaction occurs in the matrix of the mitochondria?

The Krebs cycle (citric acid cycle)

What is tonicity?

The ability of extracellular fluid to make water move into or out of a cell.

What occurs in the stroma?

The carbon fixation (Calvin-Benson cycle) of photosynthesis

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?

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 the walls, and the plant will stand upright again

What is metabolic energy (ATP) required for?

for active transport of molecules and/ or ions across the membrane and to establish and maintain concentration gradients.

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 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 to burn more energy per unit mass in order to maintain its body temp - the mouse has a higher metabolic rate than the elephant

What does selective permeability allow for?

The formation of concentration gradients of solutes across the membrane

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

The hydrophobic R groups are anchoring the protein the phospholipid membrane, as it is the water-free between the membrane layers. If those R groups were hydrophilic, the protein would fall out of the membrane and could no longer perform its function

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

Why are plasma membranes important?

The keep the internal environment of the cell separate from the external environment.

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 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

What reaction occurs in the grana?

The light dependent reactions of photosynthesis

What do Na/K ATPase contribute to

The mantiene of the membrane potential

What is selective permeability a direct consequence of?

The membrane structure

The bigger the surface area to volume ratio is...

The more efficient a cell will be when performing chemical reactions

Describe how the phospholipids of a plasma membrane regulate the movement of large or polar molecules across the membrane. Explain how osmosis will affect animal cells when the cells are placed into an environment with a low water potential (high solute concentration) compared to the intracellular water potential.

The phosopholipids are what make the cell membrane semi-permeable. Their polar, hydrophilic polar heads are on the outside and their hydrophobic, nonpolar tails are on the inside of the cell. Since the tails are on the inside, only certain materials can enter and exit. Large polar molecules need to enter through transport proteins since they are unable to enter through the membrane as they could disturb the tails. When cells are placed in a low water potential, the animal cells will shrink since the water will exit out of the cells and into the environment. Water flows from an area of high water potential to low water potential, and since the intracellular water potential was higher than the environment it was placed in, makes this situation hypertonic and making the water exit out of the animals cells which can lead to dehydration and may be fatal.

What happens when cells decrease in volume?

The relative surface area decreases and demand for internal resources increase

What does the folding of the inner membrane increase?

The surface area which allows for more ATP to be synthesized

What happens when an organism increases in size?

Their surface area to volume ratio decreases affecting properties like rate of heat exchange

Isotonic

There is the same solute concentration on both sides of the membrane(same water potential, and osmolarity)

What is the role of an aquaporin protein

They allow water molecules to move freely across the membrane into or out of the cell

Where are ribosomes found?

They are found in all forms of life, reflecting the common ancestry of all known life

Describe the phospholipids:

They have both hydrophobic and hydrophilic 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. Embedded proteins can be hydrophilic, with charged and polar side groups, or hydrophobic, with nonpolar side groups.

What do prokaryotes lack, but have?

They lack internal membrane bound organelles but have internal regions with specialized structures and functions

What happens to membranes when there is a movement of ions?

They may become polarized

What is osmolarity?

Total concentration of all solutes in the solution

How does a vacuole increase the rate that plant cells can exchange materials with their environment?

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

What is plasmolysis?

When the cell shrivels due to water loss. Plant cells do not shrivel due to their cell wall (plasma membrane disengages from the cell wall)

Predict the results of doubling the number of thylakoids on glucose production in the chloroplast. Explain;

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 row faster (more cell wall material and more energy) provided that other requirements for growth are met (sufficient nitrogen and phosphorus available)

Which of the following factors would be most likely to increase membrane fluidity? a. ​​​​​​​a greater proportion of unsaturated phospholipids b. a greater proportion of saturated phospholipids c. a relatively high protein content in the membrane d. a greater proportion of relatively large glycolipids

a. a greater proportion of unsaturated phospholipids

Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? a. oxygen b. an amino acid c. Cl- iond. starch

a. oxygen

Endocytosis and exocytosis are examples of ___________ transport

active

What do large quantities of water pass through?

aquaporins

Small, hydrophilic across cell membrane

can cross but slowly - water/carbon dioxide

Hydrophobic across cell membrane

can typically cross lipid bilayer

Large, hydrophilic across cell membrane

cannot cross, repelled by the fatty acid tails. Must use protein or vesicle to enter the cell

What do membranes contain?

chlorophyll pigments and electron transport proteins that comprise the photosystems

What does active transport require?

direct input of energy to move molecules from regions of low concentration to regions of high concentration.

Macrophage cell

do lots of endocytosis to move bacteria across the membrane

Plasma B cell:

do lots of exocytosis to move antibodies across the membrane

Palisade Plant cell

do lots of exocytosis to move glucose (sending to other cells in the plant) across the membrane

Neuron

do lots of exocytosis to move neurotransmitters across the membrane

do you think cells kill other cells on purpose? they do! when?

during controlled cell death - apoptosis

What occurs in the inner mitochondrial membrane?

electron transport and ATP synthesis

Glucose diffuses slowly through phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most likely functioning in the intestinal cells?

facilitated diffusion

What are membrane proteins required for?

facilitated diffusion of charged and large polar molecules through a membrane

Hypertonic

higher describes the side of the membrane with a higher solute concentrationHigher osmolarity Lower water potential

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

What is the Smooth ER?

in charge of detoxification and formation of new phospholipids

How would the cell lower is 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

The Na+/K+ ATPase proteins maintain a membrane potential so that the _______________ has a more negative charge compared to the _________________ of the cell

inside, outside

What happens in exocytosis?

internal vesicles fuse with the plasma membrane and secrete large macromolecules out of the cell.

How do internal membranes facilitate cellular processes?

minimizing competing interactions and by increasing surface areas where reactions can occur.

Facilitated diffusion molecules that can pass

large and/or polar - glucose, proteins, water, ions

What is the mitochondrial?

location of cellular respiration, forming ATP that powers cellular processes

Hypotonic

low describes the side of the membrane with a lower solute concentration lower osmolarity higher water potential

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 structures to prokaryotes, they have a double membrane (suggesting the other memrbane was part of the host membrane as it engulfed the smaller prokaryote) and they are about the same size as prokaryotes

What is passive transport?

net movement of molecules from high concentration to low concentration without the direct input of metabolic energy.

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

passive transport - facilitated diffusion

Endocytosis:

process by which a cell takes material into the cell by infolding of the cell membrane

Major differences between Prokaryote and Eukaryote cells

prokaryotic cells ('before nucleus') include eubacteria and archeabacteria. they don't have a nucleus or any other membrane bound organelles (though they do have ribosomes). Prokaryotic cells rely on infolding of their outer membranes to perform tasks such as photosynthesis and aerobic cellular respiration. Their DNA is circular, and includes small rings called Plasmids which can be transferred from one prokaryotic cell to another. Prokaryotic cells are small. They sometimes have peptidoglycan cell walls for protection and osmoregulation

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 Electron Transport Chain. 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 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 does this suggest about the history of life (parts found in eukaryotic and prokaryotic cells)

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

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

the mitochondria could do aerobic respiration, embedding the Electron Transport Chain on infoldings of its membrane - as many prokaryotes do today. the chloroplast could do photosynthesis to make its own glucose, but then must also have done some form of respiration to make ATP

Where does the light dependent reaction take place?

thylakoid membranes

What is the function of ribosomes?

to synthesize proteins (following instructions from mRNA)

What are aquaporins?

transport proteins (channel proteins) that move water

What is the vacuole?

used for storage of water and other dissolved compounds needed by the cell. Large central vacuole in plants also used for support to hold up the cell wall

Osmosis is the diffusion of

water across the membrane

What does osmoragulation maintain?

water balance and allows organisms to control their internal solute composition/water potential.