Chapter 4 Bio NCTHS
Polypeptides are assembled from _____.
amino acids Proteins are composed of amino acid monomers.
What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?
cell wall; is a rigid supporting structure
which organelles comprise the endomembrane of the a cell?
endoplasmic reticulum, golgi apparatus, and lysosome
RNA processing converts the RNA transcript into _____.
mRNA The editing of the RNA transcript produces mRNA.
mitochondrion (plural: mitochondria)
produces energy needed for cellular processes (appears in both plant and animal cells)
In a bacterium, where are proteins synthesized?
ribosomes, are involved in the manufacture of polypeptides (proteins)
endoplasmic reticulum (ER)
system of channels that move materials around the cell (subway); rough = ribosomes, smooth = no 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 functions to produce proteins for the endomembrane system and is involved in alcohol metabolism. This organelle is affected in the liver cells of alcoholics.
During a bacterial infection, signals are produced that communicate with the nucleus via molecules found on the surface of specific cells. This allows for the recruitment of white blood cells. What molecules are communicating with the nucleus?
integrins integrins span the membrane and integrate signals, transmitting information between the extracellular matrix and the cytoskeleton of the cell.
The plant cell wall
is a protective structure made of cellulose fibrils. The cell wall is a structure that protects the plant cell and is made of cellulose fibrils.
The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. Which organelle is most likely failing to function correctly?
lysosome This organelle functions to remove unwanted or unneeded material from the cell.
What is one organelle that is only found in animal cells?
lysosome; this organelle is found only in animal cells. plants have a similar organelle called the central vacuole
cell membrane
outer boundary of the cell; regulates the substance that enter and exit the cell (bouncer)
golgi-apparatus
packages proteins for transport and use outside cell
Animal cell are surrounded by a ____________, whereas plant cells are also surrounded by a _________.
plasma membrane, cell wall
The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.
plasma membrane, selectively permeable
chloroplast (only in plant cells and some bacterium)
site of photosynthesis; uses the sun's energy to make food for the plant; contains chlorophyll
_____ are surface appendages that allow a bacterium to stick to a surface.
fimbriae; fimbriae enable bacterial cells to stick to a surface
What name is given to the process in which pre-mRNA is edited into mRNA?
RNA processing RNA processing edits the RNA transcript that has been assembled along a DNA template
The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter ___.
C; the plasma membrane is selectively permeable
In human females, an ovum (egg cell) is not released directly from the ovary into the oviduct. Which mechanism below is the best explanation for how the ovum makes it into the oviduct?
Cilia located at the opening of the oviduct capture the ovum in a sweeping motion. Cilia also line the oviduct and sweep the ovum in the direction of the uterus
The DNA containing region of this bacterial cell is indicated by the letter ____.
D; the nucleoid region contains DNA (bacterium do not have nuclei)
Which of the following describes the function of the chloroplast?
The chloroplast converts light energy to chemical energy The chloroplast makes food for the plant cell by converting light energy to chemical energy
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. Or the finished products become part of the plasma membrane or part of another organelle.
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.
_____ are found only in plant cells, but _____ are found in both plant and animal cells
central vacuoles; ribosomes Central vacuoles are found only in plant cells. ribosomes are found in both plant and animal cells
Many researchers think that the first eukaryotic cells consumed the organic compounds needed for life-sustaining functions. Given this information, which of the following organelles most likely appeared last in eukaryotic cells?
chloroplasts If the earliest eukaryotic cells had contained chloroplasts, they would not have had to obtain organic compounds through food.
what are three organelles that plant cells have but animal cells do not?
chloroplasts, central vacuole, cell wall
plant cells have two energy-related organelles. ________ harness light energy to create sugars and ____________ break down these sugars to create ATP.
chloroplasts; mitochondria
mitochondrion
converts chemical fuel into packets of chemical energy (ATP) that can power the cell
nucleus (plural: nuclei)
directs the cell's activities; contains the hereditary material of the cell (DNA)
The __________ builds compounds, whereas the ____________ breaks things down.
endoplasmic reticulum; lysosome
label the parts of a bacteria, animal, and plant cell
http://www.sheppardsoftware.com/health/anatomy/cell/index.htm
cytoplasm
jelly-like substance, consisting mostly of water, that is the medium through which materials pass inside the cell
ribosome
make proteins according to genetic instructions (worker bees)
chloroplast
makes food by converting light energy into chemical energy
vacuole (central vacuole: plant cell)
membrane-enclosed sac that stores food, water, and other materials
The cilia and flagella of eukaryotic cells are composed of _____.
microtubules eukaryotic cilia and flagella are composed of microtubules.
Which of the following cytoplasmic structures functions in the transport of vesicles from the endoplasmic reticulum to the Golgi apparatus?
microtubules Vesicles travel along microtubules as they move from one part of the cell to another.
Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell?
mitochondrion; in both plant and animal cells, it's the mitochondria that convert chemical fuel into packets of chemical energy that can power the cell.
golgi apparatus
modifies and packages proteins
Where is a bacterial cell's DNA found?
nucleoid region; bacteria lack a nucleus; their DNA is found in the nucleoid region
Which plant structure is most like gap junctions in animal cells?
plasmodesmata plasmodesmata form channels between adjacent plant cells which have a similar function to gap junctions in animal cells.
What is one characteristic that would distinguish a bacterial cell from an animal cell?
presence of cell wall; prokaryotic cells have cell walls. some eukaryotic cells do also (plant cells), but animal cells do not
What is the function of bacterium's capsule?
protection; a bacterium's capsule has a protective role
lysosome
recycling and maintenance; helps maintain and repair cell structures; digests wastes and worn-out parts
central vacuole
regulates cytoplasm composition, creates internal pressure, and stores cell compounds
cell wall (only in plant cells and some bacterium)
rigid outer covering of plant cell; made of cellulose and found outside the cell membrane
Which of the following is a function of the central vacuole?
storing compounds produced by the cell; one of the functions of the central vacuole is to store compounds produced by the cell
plant cell wall
strong, protective structure made from cellulose fibrils
the plasma membrane would fit into which general function category?
support, movement, and communication the plasma membrane is an important structure for cell communication with the external environment
One function of the central vacuole in plants is growth. The central vacuole grows larger when there is an increase in the amount of stored material. An animal cell does not grow by this method. What is the essential difference between animals and plants that requires the central vacuole?
the plant cell wall provides a more rigid structure The plant cell uses the central vacuole for growth because the cell wall is rigid.
What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?
transcription Transcription is the process by which a DNA template is used for the manufacture of several different types of RNA
In eukaryotic cells the first step in protein synthesis is the _____.
transferring of information from DNA to messenger RNA Transcription is the first of the two main steps of protein synthesis.
What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?
translation Translation is the process by which information encoded in RNA is used to manufacture a polypeptide.
chromatin
uncoiled bundles of DNA, the genetic materials of the cell; inside the nucleus
