biology ch 4
The genetic center of the eukaryotic cell is the __________.
Nucleus
What does the rough ER do?
makes additional membrane for itself and proteins destined for secretions
Where is a bacterial cell's DNA found?
nucleoid
Endomembrane system
The endomembrane system is involved in the synthesis, storage, and export of important molecules. The endomembrane system includes the nuclear envelope. The endomembrane system includes the rough and smooth endoplasmic reticulum
How are cell surface proteins exported out of the cell?
The protein is folded, then packaged for transport to the Golgi apparatus. The protein structure is critical to the normal function of the protein. Once folded, then it will be transported to the Golgi apparatus via a transport vesicle.
What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?
They are constructed of interrelated membranes
what do rough er, golgi apparatus, and lysosomes have in common?
They are constructed of interrelated membranes. Each of these organelles is a member of the endomembrane system and is constructed of the same type of membrane.
A certain cell has a dense nucleoid region, ribosomes, but no membrane-enclosed organelles. Based on this information, it could be __________
an Archaean (any prokaryotic)
Peroxisomes are organelles that are involved in the
breakdown of fatty acids. Peroxisomes break down fatty acids for fuel, and they are involved in the detoxification of alcohol and other harmful substances
What structure is used by prokaryotic cells for attaching to surfaces?
capsule
The complex of proteins and DNA in a nondividing cell is called
chromatin
Which of the following are stored in the lysosomes of the cell? material to make ribosomes digestive enzymes glycoproteins being prepared for secretion from the cell enzymes for detoxifying harmful compounds such as alcohol
digestive enzymes. Lysosome is a sac of digestive enzymes.
contractile vacuole
eliminates excess water from the cytoplasm of freshwater protists. The cell structure that collects extra water from the cytoplasm and then expels it from the cell. It keeps the freshwater protists in osmotic balance.
Protein synthesis requires the use of mRNA, which
is translated by the ribosomes into the amino acid sequences of proteins
The main function of the rough endoplasmic reticulum is the production of
membrane and proteins secreted by the cell
Which of the following is NOT a part of the endomembrane system? Golgi apparatus endoplasmic reticulum mitochondria vesicles
mitochondria
The membranes of the endoplasmic reticulum are continuous with the membranes of the __________.
nuclear envelope
You have identified a new organism. It has ribosomes, plasmodesmata, and cell walls made of cellulose. This new organism is most likely a(n) __________.
plant
what does smooth er do
produces enzymes important in synthesize of lipids, oils, phospholipids, and steroids
The main function of the rough endoplasmic
production of membrane and proteins secreted by the cell
What cells are archaea composed of?
prokaryotic cells
Which of the following structures is found in prokaryotic cells? (ribosomes, nucleus, ER, mitochondria)
ribosomes
The cells that produce hair made of protein contain a lot of ________, while the cells that produce the oils that coat the hair contain a lot of ________.
rough ER, smooth ER
GPCRs are receptor proteins found in the plasma membrane that are important for cellular communication. What cellular structure makes GPCRs?
rough endoplasmic reticulum
In muscle cells, the _____ is/are specialized for the storage and release of calcium.
smooth endoplasmic reticulum. When a muscle cell is stimulated by a nerve impulse, calcium is released from the smooth ER, triggering the contraction.
Smooth endoplasmic reticulum
stores calcium ions in muscle cells
Golgi apparatus function
stores, modifies, and packages proteins
functioning of rough ER
synthesizing receptor proteins, produce proteins for the rest of the cell to function
The function of the nucleolus is
to manufacture ribosomal RNA
A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they
have gained water and burst
An immune system cell called the plasma cell produces thousands of antibodies (a type of protein) per second for release into the body. What type of intracellular structure would you expect to be very prominent within the cell?
rough endoplasmic reticulum
The cells that produce hair made of protein contain a lot of ________, while the cells that produce the oils that coat the hair contain a lot of ________.
rough endoplasmic reticulum; smooth endoplasmic reticulum
You would expect a cell with an extensive Golgi apparatus to _____.
secrete a lot of material.
What does the membranous compartmentalization do?
Allow different chemical conditions to be maintained in different parts of the cell
A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually used to build a cell's plasma membrane. The protein in the membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the _____.
Golgi apparatus. Vesicles carrying proteins from the ER fuse with the Golgi apparatus, where the proteins may be altered.
Which of the following statements about lysosomes is false? Lysosomes destroy harmful bacteria engulfed by white blood cells. Lysosomes synthesize proteins from the recycled amino acids. Lysosomes help to digest worn-out or damaged organelles. Lysosomes fuse with food vacuoles to expose nutrients to lysosomal enzymes.
Lysosomes synthesize proteins from the recycled amino acids.
What is found in only animal cells and sometimes plant?
Lysosomes- most plant cells don't have lysosome
You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude correctly that the cells
Plant cells
What would distinguish a bacterial cell from an animal?
Presence of a cell wall
Which of the following is the most likely consequence for a cell lacking functional lysosomes? The cell dies from a lack of enzymes to catalyze metabolic reactions. The cell is unable to grow to a mature size and always remains small. The cell dies because its ATP-synthesizing mechanisms are missing. The cell becomes crowded with undigested wastes.
The cell becomes crowded with undigested wastes.A lysosome is a membrane-enclosed sac of hydrolytic enzymes that the cell uses to digest macromolecules—in some cases, recycling the cell's own organic material.
Which of the following statements about the functions of a plant cell central vacuole is false? The central vacuole of a plant cell may help increase the size of cells by absorbing water. The central vacuole of a plant cell may store waste products. The central vacuole of a plant cell may digest chemicals for recycling. The central vacuole of a plant cell may store poisons.
The central vacuole of a plant cell may digest chemicals for recycling.
What is the relationship between the Golgi apparatus and the plasma membrane
The finished products of the Golgi apparatus may leave the cell through vesicles that fuse with the plasma membrane. Transport vesicles from the Golgi move to the plasma membrane for export. In some cases the finished products become part of the plasma membrane or part of another organelle
What do prokaryotic cells lack?
a membrane enclosed nucleus
Which is a typical function of lysosomes?
breaking down of damaged organelles, such as mitochondria. Lysosomes do break down damaged organelles; lysosomes are rarely found in plant cells.
What do contractile vacuoles help prevent?
cells from bursting as a result of the influx in water
During cell reproduction, chromatin fibers coil up into structures called
chromosomes
Membrane proteins are synthesized by ribosomes that are attached to __________.
endoplasmic reticulum
Membrane proteins are synthesized by ribosomes that are attached to _______
endoplasmic reticulum. Ribosomes bound to endoplasmic reticulum generally make proteins destined either for inclusion into membranes; for packaging within certain organelles, such as lysosomes; or for export from the cell. The ribosomes attached to its surface are what give the RER its "rough" appearance.
Hexokinase is an enzyme that is involved with glycolysis (the breakdown of glucose for energy release) that occurs in the cytoplasm. What cellular structure makes hexokinase?
free ribosomes
What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?
increased levels of endoplasmic reticulum activity. The smooth endoplasmic reticulum of liver cells has enzymes that are involved in alcohol metabolism. This organelle is affected in the liver cells of alcoholics.
What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?
increased levels of endoplasmic reticulum activity. explanation: The smooth endoplasmic reticulum of liver cells has enzymes that are involved in alcohol metabolism. This organelle is affected in the liver cells of alcoholics.
Bacterial cells are prokaryotic, meaning they______
lack a nucleus
What is part of the endomembrane system?
nuclear envelope, lysosomes, vesicles, the ER, and Golgi apparatus, as well as the plasma membrane.
What of the following structures is only associated with prokaryotic cells?
nucleoid (it has no nucleus)
Digestive cells produce and secrete many enzymes that break down ingested food. These cells have a large number of ribosomes __________.
on the rough ER. The rough endoplasmic reticulum is responsible for producing proteins that will be inserted into membranes, packaged in certain organelles, or exported from the cell.
Digestive cells produce and secrete many enzymes that break down ingested food. These cells have a large number of ribosomes __________.
on the rough endoplasmic reticulum. The rough endoplasmic reticulum is responsible for producing proteins that will be inserted into membranes, packaged in certain organelles, or exported from the cell.
Structures found within a eukaryotic cell and performing specific tasks are collectively termed __________.
organelles
Secretory proteins are
released from the cell through the plasma membrane
Secretory proteins are
released from the cell through the plasma membrane.
What happens in the nucleolus?
ribosomal RNA is synthesized , RNA combines with special proteins and forms the ribosomes.
Of the following organelles, which group is involved in manufacturing the substances needed by the cell? lysosome, vacuole, ribosome smooth endoplasmic reticulum, ribosome, vacuole vacuole, rough endoplasmic reticulum, smooth endoplasmic reticulum ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum
ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum. Each structure is capable of synthesis
An immune system cell called the plasma cell produces thousands of antibodies (a type of protein) per second for release into the body. What type of intracellular structure would you expect to be very prominent within the cell?
rough ER
GPCRs are receptor proteins found in the plasma membrane that are important for cellular communication. What cellular structure makes GPCRs?
rough ER
The oil from the sebaceous glands is produced by which of the following cell organelles?
smooth ER
In muscle cells, the _____ is/are specialized for the storage and release of calcium.
smooth ER. When a muscle cell is stimulated by a nerve impulse, calcium is released from the smooth ER, triggering the contraction.
The skin is the body's largest organ. It's made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The pigment melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function. The oil from the sebaceous glands is produced by which of the following cell organelles?
smooth endoplasmic reticulum
What does the smooth endoplasmic reticulum do?
stores calcium ions in muscle cells
Golgi Apparatus
stores, modifies, and packages proteins.
Which of the following is a function of the rough endoplasmic reticulum? synthesizing receptor proteins synthesizing steroid hormones storing calcium ions detoxifying drugs
synthesizing receptor proteins. These proteins are made by the rough endoplasmic reticulum and then processed by the Golgi apparatus before being inserted into the cell membrane.
Lysosomes are derived from __________ and function in __________.
the Golgi apparatus and rough endoplasmic reticulum ... digestion of worn-out organelles
What does the nucleoid of a prokaryotic cell contain?
the cell's DNA
Which of the following structures is essential for the successful operation of the endomembrane system? centrioles chloroplasts anchoring junctions transport vesicles
transport vesicles Transport vesicles provide a means for moving materials from one part of the endomembrane system to another.
What clue would tell you whether a cell is prokaryotic or eukaryotic?
whether or not the cell is partitioned into compartments by internal membranes