Cell Organelles / First Quiz Gr 12 Flashcards
What is the function of the chloroplasts?
Chloroplasts collect sunlight to then create energy through photosynthesis, which is the process of using light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars (glucose) and starches?
Where are chloroplasts mainly found in the plant - be specific!! Why is it good that they’re found there?
They can be found mainly in plant leaves because that is where they have the most surface area to access sunlight.
What is the function of mitochondria? What type of cells contain a lot of them?
The Mitochondria creates energy by converting food into chemical energy (ATP) needed for all other cell processes.
Muscle, brain, and nerve cells contain lots of mitochondria because they require more energy to move, and push blood through the body.
What are some structural similarities between the chloroplast and mitochondria?
Both of these organelles share the same function of creating energy
Structure wise both organelles have both an inner and outer membrane, and an inter membrane space, so they are double membrane bound organelles, and they both contain their own genetic material. (DNA)
Which is bigger? chloroplast or mitochondria?
The Chroloplast is bigger as it needs a bigger area to collect sunlight and to complete processes like the calvin cycle, Chloroplasts have a much more complex process compared to the mitochondria, hence why they need more space to complete these processes, and they need the extra room to store starch grains.
What is the function of the cell wall?
The cell wall is used to maintain cell structure and protect the cell.
What is the cell wall made of?
The cell wall is made up of polysaccharides cellulose, hemicellulose, and pectin.
describe what the cell wall looks like. How does this help with its function?
It wraps around the exterior of the cell, to protect all of the cell’s organelles.
The cell wall has to be tough, flexible, and sometimes rigid to complete its function of providing structure protection.
Which cells have a cell wall, why?
Only plant cells have a cell wall because it acts as an exoskeleton for each cell, providing the cell with crucial structural support and rigidity, which enables plants to stand upright even without bones.
This also makes it hard to move hence why animal cells do not have cell walls.
What do cells that don’t have a cell wall have instead?
A Cytoskeleton
What is the main difference between Cilia and Flagella structually?
Cillia are like a bunch of little hair like membranes that move together to transport different molecules and cells. Whereas flagella are a singular Hair like membrane that whips around to propel through the cytoplasm.
Give an example of a type of cell or organism that has a Flagella
Sperm cells have flagella in order to propel and deliver genetic material to an egg cell during sexual reproduction.
Give an example of a type of cell or organism that has cilia
cilia can be found in the lungs; used to remove harmful microbes and debris.
What is the difference between the hydrophobic and hydrophilic ends of phospholipids?
Hydrophobic tails, as the name suggests are the tails of a phospholipid which never come in contact with water so they are found in the interior.
Whereas hydrophilic heads are water loving and always face the exterior side of the phosphate bilayer.
Describe how the phospholipids are arranged/how they line up.
Hydrophobic tails align facing each other avoiding water, hence the name hydro-phobic. The hydrophilic head always faces outwards touching the water, hence the name hydrophilic.
What is the function of the cell membrane?
The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.
Why is the model of the cell membrane often called the fluid mosaic model?
Because it is made up of so many essential small parts such as the phospholipids, their heads and tails, as well as recognition proteins, receptor proteins, and transport proteins.
What is the function of the nucleus?
The nucleus stores the genetic information (DNA) of the cell.
Describe the structure of the nuclear envelope.
The nuclear envelope is the outer membrane of the nucleus (it provides structure and separates the nucleus from the cell’s cytoplasm), it has nuclear pores throughout and holds chromatin as well as the nucleolus.
What is the relationship between DNA, chromosomes and chromatin?
DNA condenses with proteins into two sister chromatin, which then becomes a singular chromosome.
What does a nuclear pore look like and what is its function?
Nuclear pores are tiny openings found on the nuclear envelope.
Nuclear pores allow for ions and small molecules to pass or diffuse in or out of the nucleus (specific proteins that belong in the nucleus can also pass through these pores).
What is the function of the nucleolus and where is it found?
The nucleolus is found within the nucleus.
The function of the nucleolus is to produce ribosomes. (ribosomes then produce proteins)
How does the size of the nucleus compare to the size of the mitochondria and chloroplast?
The Nucleus is visibly bigger then the two.
What is the function of the rough and smooth endoplasmic reticulum?
The rough endoplasmic reticulum produces proteins that are then transported to the golgi apparatus by the smooth endoplasmic reticulum, the SER also produces enzymes and lipids that are also transported, lipids are transported through vesicles and then released into the cytoplasm
Describe the general structure of the endoplasmic reticulum. How is the structure well-suited for its function?
The Endoplasmic reticulum can be found near the nucleus, it is made of many folded membranes that help transport essential materials throughout the cell.
The rough endoplasmic reticulum (RER) is found closer to the nucleus, and gets its rough textured look because of ribosomes embedded in the membrane.
The smooth endoplasmic reticulum (SER) is smooth because it does not have any ribosomes attached.
What is the function of the golgi apparatus?
The Golgi apparatus is in charge of receiving vesicles sent by the smooth ER, then it merges the proteins and other materials (lipids,ect) from the vesicle to those within the Golgi apparatus, finally it adds or modifies proteins to then release the vesicle back onto the cell or into the cell membrane to be excreeded from the cell.
How does the structure of membranes and sacs help with its function? (Golgi Apparatus)
The Golgi apparatus is essentially a stack of curved membrane sacs (looks like pancakes) ; these sacs are called cisternae.
Vesicles from the SER merge into the cisternae where other proteins are stored for modifications
Describe the basic structure and function of lysosomes.
It’s a little sac filled with digestive enzymes that are used to break down and remove cell waste.
What do lysosomes contain and why are they often called suicide sacs?
Lysosomes contain digestive enzymes (hydrolytic enzymes)
They are often called Suicide Sacs because if a damaged lysosome were to burst the enzymes inside will eat the very cell they reside in.
compare the sizes of Vacuoles and Vesicles, How is their structure similar?
Vacuoles are visibly bigger than vesicles.
Both have a sac structure.
How are Vacuoles and Vesicles different in plant and animal cells?
In plant cells the vacuole is much bigger than in animal cells and you will find one main a Central vacuole or a water vacuole in plant cells.
In animal cells vacuoles are much smaller similar to vesicles, and there is more than just one.
What are the functions of Vacuoles and Vesicles?
Vesicles are used to transport and to store proteins enzymes, hormones and other cell materials (for example Lysosomes and ribosomes, neurotransmitters)
Vesicles can also fuse with other membranes within the cell system. (Vesicles from the ER fuse into the cisternae of the golgi apparatus.)
Vesicles can be found in both plant cells and animal cells.
Vacuoles are used for storage of food, water, and starches.
How are vesicles related to the golgi apparatus?
The Golgi apparatus receives vesicles from the smooth endoplasmic reticulum and then modifies or repackages them back into vesicles, then releasing them back into the cytoplasm of the cell.
what is the difference between active transport and passive transport?
Active transport requires energy, where passive transport does not.
what is passive transport?
passive transport is the movement of ions and molecules along the concentration gradient without the application of any external energy.
What is an example of passive transport?
Osmosis and diffusion are examples of passive transport.
What is a diffusion? example?
a diffusion is the movement if particles from high concentrations to an area of low concentration until an equilibrium is reached. (have equal concentrations)
osmosis is an example of diffusion where high concentrations of water molecules defuse into low concentrations of water.
Why does passive transport not require any energy?
There is no need for energy because the molecules are small enough to be able to pass through without needing energy to physically push through.
What does diffusion require?
It requires a concentration gradient, the greater this gradient is the faster diffusion will occur.
What is osmosis?
The diffusion of water through a semi permeable membrane.
Water molecules are able to pass through the cell membrane in this way (without energy) because it is a small molecule
what is facilitated diffusion?
THERE MUST BE A CONCENTRATION GRADIAN FOR THIS TO OCCUR.
It is the transportation of molecules using a transport protein, found in the cell membrane.
Large or hydrophilic molecules usually enter this way, for example glucose enters the cell using facilitated diffusion as the molecules are to big to pass through the cell membrane
what does it mean for a solution to be isotonic?
The concentration of the solute and solvent is the same on both sides of the cell membrane.
No movement of water
(flaccid or normal)
what does it mean for a solution to be hypertonic?
Hypertonic solutions have a higher concentration of solute inside the cell (ex sodium) compared to another solution, or the outside of the cell (ex Water).
water will move out of the cell making it plasmolyzed (shrivelled)
what does it mean for a solution to be hypotonic?
Hypotonic solutions have a lower concentration of solute inside the cell (ex sodium) compared to another solution outside of the cell (ex water).
Water will move into the cell making it turgid (normal)
what are Intrinsic or integral proteins? Examples?
Intrinsic or integral proteins are permanently attached to the bilayer, and extend through the cells hydrophobic core.
For example recognition, receptor, and transport proteins are all integral proteins.
