Ap bio Chapter 4
Animal cells do not have cell walls but they have an extracellular matrix(ECM). What is the role of ECM?
(animal cell connection) It connects tissue within an organism.
Cell Theory (3 parts)
1. All living things are made of cells. (Robert Hooke) 2. Cells are the basic unit of structure and function in organisms. (Schleiden & Schwann) 3. All cells come from other cells. (Virchow)
list three major functions of the smooth Er
1. Detoxifies poisons, 2. metabolizes carbohydrates, and 3. Building of lipids.
What are the two components of chromatin? When do the thin chromatin fibers condense to become distinct chromosomes?
DNA and Histone proteins, In eukaryotic cells they do it during cell division.
Animal cell connection junctions
Desmosomes=Anchoring junctions.
what is the function of ribosomes
They make proteins.
Animal cells do not have plasmodesmata. Summarize the role of the three types of intercellular junctions seen in animal cells.
Tight Junctions:general function is to prevent leakage of transported solutes and water and seals between adjacent cells. Desmosomes: Anchoring junctions that prevent cells from being pulled apart. Gap junctions: tunnels that connect cytoplasm of adjacent animal cell.
nucleolus (plural, nucleoli)
a nuclear region that functions in the synthesis of ribosomes
What is the function of the chloroplasts?
allow plants to capture the energy of the Sun in energy-rich molecules
What are microvilli? How do these structures relate to the function of intestinal cells?
are microscopic cellular membrane protrusions that increase the surface area for diffusion and minimize any increase in volume. Microvilli are long, thin projections from the cell surface, which increase surface area without an appreciable increase in volume.
What is the composition of the plant cell wall?
cellulose
Chromosomes are made of
chromatin
Plasma Membrane:
encloses the cell and separates the inside from the outside. Regulates what goes in and out of cell. (AKA cell membrane)
What is the function of the mitochondria?
generate most of the chemical energy needed to power the cell's biochemical reactions.
What is the cytoskeleton? what are two main roles of the cytoskeleton?
is a network of protein fibers that runs throughout the cytoplasm. 1. they give the cell shapes in animal cells, 2. it helps moving things they make almost like railroad tracks inside the cell.
what does the ER do with these secretory proteins?
it puts them in a vesicle and sends it to the golgi.
Vacuoles and central vacuole( differences)
A plant cell contains a large, singular vacuole that is used for storage and maintaining the shape of the cell. In contrast, animal cells have many, smaller vacuoles.
What happens in the Tay-Sachs disease? Explain the role of lysosome in Tay-Sachs.
Accumulation of lipids inside the brain, lysosomes help with it because it breaks down those lipids so that the problem gets solved.
bound ribosomes, Location and product.
Are attached to the endoplasmic reticulum and make proteins destined for export from the cell. (proteins that are used outside the cell)
Why does alcohol abuse increase tolerance to other drugs such as barbiturates?
Barbiturates, alcohol, and many other drugs induce proliferation of smooth ER which are associated with detoxification enzymes, thus increasing rate of detoxification.
Explain the important role played by peroxisomes?
Break down (organic molecules)acids(are bad) to produce hydrogen peroxide which is converted to water or used to break down alcohol.
Why are cells so small? Explain the relationship of surface area to volume.
Cells Must Be Small. Cells stay small to keep the surface to volume ratio big. As a cell increases in size, its volume grows proportionately more than its surface area. The SA must be large enough for the cell volume in order to provide an adequate exchange surface for oxygen, nutrients and waste.
Compare and contrast cilia and Flagella.
Cilia: Short and in numerous in numbers(unique to eukaryotes). Flagella: is a long whip like tail usually low in numbers( can be on both types of cells)
nuclear envelope? How many layers is it? What connects the layers?
Encloses the nucleus, separating its contents from the cytoplasm. The nuclear envelope is a double membrane composed of an outer and an inner phospholipid bilayer. the two layers connect with the lumen of the rough endoplasmic reticulum
What is a lysosome? what do they contain? at what ph range do they work the best?
IS a vesicle that comes from the golgi but it does not leave the cell, it contains digestive enzymes that work in an acidic PH.
A second function of lysosomes is to recycle cellular components in a process called AUTOPHAGY. Describe this process.
It a process of recycling non working things inside the cell.
What are three functions of the cell wall?
It's present in prokaryotes and plants. Keep cell in shape. prevent it from damage. Helps it connect to other cells.
Prokaryotic cell structure
Look at pictures in your phone
what is not considered a part of the endomembrane system?
Mitochondria and chloroplasts.
Vacuoles
Stores food, water, wastes, and other materials( are large vesicles)
What are the intercellular Junctions between plant cells? what can pass through these?
Plasmodesmata are intercellular junctions between plant cells that enable the transportation of materials between cells.
Magnification and resolving power limit what can be seen. Explain the difference.
Resolving power: Ability of the microscope to show detail. Magnification: Ratio of an object's image size to its real size.
The surface area-to-volume ratio of a cell
Surface area/volume
One function of lysosomes is intracellular digestion of particles engulfed by phagocytosis. Describe this process of digestion. What human cells carry out phagocytosis?
The cell rearranges its membrane to surround the particle that is to be phagocytosed and internalises it. White blood cells.
Bacterial chromosome
The chromosome is the genetic material of the bacterium.
What is an endosymbiont?
The endosymbiont theory proposes that mitochondria and chloroplasts share a similar origin. This theory states that these organelles were engulfed by ancestors of eukaryotic cells. Evidence: Both organelles have a double-membrane structure, Both organelles have their own ribosomes and circular DNA molecules, Both organelles reproduce independently within the cell.
Why is the inner membrane of mitochondria highly folded? what role do all individual thylakoid membranes serve?
The many folds in the inner membrane of mitochondria and the many individual thylakoid membranes serve to increase the organelle's surface area without greatly increasing its volume.
besides packaging secretory proteins into transport vesicles, what is another major function of the rough Er?
The membrane keeps them separate from proteins that are produced by free ribosomes and will remain in the cytosol.
When are the nucleoli visible? What are assembled here?
They are visible when ribosomal(rRNA) are being assembled. ribosomes are assembled here from instructions in the DNA.
Describe what happens to a transport vesicle and its contents when it arrives at the golgi apparatus.
proteins from the transport vesicles of the ER are received, sorted, folded, chemically modified as needed, and thin shipped
Nucleoid
region where the cell's DNA is located (not enclosed by a membrane)( in prokaryotic cells)
Cell wall
structure around the cell membrane that provides structure and support.
Free ribosomes, Location and product.
suspended in cytosol which will function in cytosol (ex:enzymes) (floats in the cytosol). Make proteins that are immediately needed. ( make proteins used inside the cell)
Cytoplasm
the fluid of the cell. (AKA cytosol)
Flagella
whiplike tails found in one-celled organisms to aid in movement
