chp.3 homework Flashcards
Which of the following are the three main parts of a human cell?
mitochondria, lysosome, and centriole
cytoplasm, plasma membrane, and nucleus
plasma membrane, mitochondria, and nucleus
cytosol, nucleus, and membrane
cytoplasm, plasma membrane, and nucleus
Which of the following statements is not one of the major concepts of the cell theory?
-The function of a cell dictates the chemical structure and organelles of the cells.
-The cell is the basic structural and functional unit of living organisms.
-Cells only arise from other cells.
-The activity of an organism emerges from the individual combined activities of the different cell types within an organism.
The function of a cell dictates the chemical structure and organelles of the cells.
Which of the following is a component of the plasma membrane that creates a physical barrier between the inside and the outside of the cell?
water
proteins
phospholipids
cholesterol
phospholipids
Which of the following allows for communication and the passage of small molecules between adjacent cells?
desmosome
glycocalyx
gap junction
tight junctions
gap junction
Which component of the plasma membrane might allow the body to recognize cells as “self” (its own) or “non-self” (foreign)?
Cholesterol
Phospholipid
Protein
Carbohydrate
carbohydrate
In this course, you will learn about hormones and their effects on cells. Certain hormones bind to receptors at the plasma membrane to “deliver” their message to the cell. What function of the plasma membrane is this?
Cell-to-cell recognition
Communication
Selectively permeable
Physical barrier
Communication
Which of the following best explains diffusion?
- movement of molecules from an area of high concentration to an area of low concentration
- movement of molecules farther away from equilibrium
- movement of molecules from where there are fewer of them to where there are more
- exchange of nonpolar molecules for polar molecules
movement of molecules from an area of high concentration to an area of low concentration
Which of the following is most likely to move through the cell membrane by facilitated diffusion?
CO2
O2
Na+
small lipids
Na+
What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?
- In simple diffusion, molecules move down the concentration gradient but in facilitated diffusion molecules move up the concentration gradient.
- In facilitated diffusion, molecules only move with the aid of a protein in the membrane.
- Simple diffusion is passive but facilitated diffusion is an active process that uses energy.
- Simple diffusion requires molecules to move through special doorways in the cell membrane.
In facilitated diffusion, molecules only move with the aid of a protein in the membrane.
Which of the following is least likely to increase the rate of diffusion?
higher concentration of molecules
small concentration gradient
small molecule size
high temperature
small concentration gradient
What is the difference between active and passive transport across the plasma membrane?
-Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane.
-Active transport means that the cell is aggressively going after substances that it wants to bring into the cell, whereas passive transport means that the cell just waits for the substance to cross the membrane.
-Active transport implies that the cell is working with other cells, whereas passive transport implies that the cell does not cooperate with other cells.
- Active transport is used to move substances down their concentration gradient, whereas passive transport is used to move substances against their concentration gradient.
Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane.
Which of the following is a difference between primary and secondary active transport?
-Primary active transport is driven by secondary active transport.
-Primary active transport moves solutes in opposite directions while secondary transport moves solutes in the same direction.
-In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated.
-Energy is required for both primary active transport and secondary active transport.
In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated.
Which of the following statements is true?
Exocytosis involves infolding of the plasma membrane.
Endocytosis and exocytosis are passive transport mechanisms.
Unlike endocytosis, exocytosis does not rely on protein interactions with the plasma membranes.
During exocytosis, substances from inside the cell are moved outside.
During exocytosis, substances from inside the cell are moved outside
Active Processes:
Active Transport, Endocytosis, Exocytosis
Passive Processes:
Diffusion, Facilitated Diffusion, Osmosis, Filtration
What is a membrane potential?
-the possibility of a membrane-based cell activity
-cooperation between cells involving membrane interactions
- a voltage or electrical charge across the plasma membrane
-the types of integral membrane proteins associated with a particular cell membrane
a voltage or electrical charge across the plasma membrane
Which of the following is FALSE regarding the membrane potential?
The resting membrane potential is determined mainly by the concentration gradients and differential permeability of the plasma membrane to K+ and Na+ ions.
The resting membrane potential is maintained solely by passive transport processes.
In their resting state, all body cells exhibit a resting membrane potential.
The resting membrane potential occurs due to active transport of ions across the membrane due to the sodium-potassium pump.
The resting membrane potential is maintained solely by passive transport processes.
Hormones and neurotransmitters are examples of second messengers used in chemical signaling.
True
False
False
When tissues are injured or infected, chemical signals can be released that affect the plasma membrane of cells that line the nearby blood vessels. These blood vessels’ cells (endothelial cells) respond to the chemical signals by displaying a type of glycoproteins on their surface. These proteins will attach to circulating white blood cells bringing them to the site of injury or infection. These glycoproteins would best be described as ________.
Cell Adhesion Molecules (CAMs)
Which of the following organelles is correctly paired with its function?
lysosome: protein synthesis
mitochondrion: packaging proteins and lipids
Golgi apparatus: produces energy for the cell
smooth endoplasmic reticulum: metabolism of lipids
smooth endoplasmic reticulum: metabolism of lipids
Two genetic diseases, Hunter and Hurler syndromes, are caused by an inability of cells to break down and recycle mucopolysaccharides, which are substances found in the extracellular areas of the body. Which organelle is responsible for performing this function in normal cells?
Endoplasmic reticulum
Mitochondria
Golgi apparatus
Lysosomes
Lysosomes
The functions of centrioles include ________.
serving as the site for ribosomal RNA synthesis
organizing the mitotic spindle in cell division
providing a whiplike beating motion to move substances along cell surfaces
producing ATP
organizing the mitotic spindle in cell division
Which of the following is characteristic of cilia?
They increase the surface area of absorptive cells in the kidneys and intestines.
They are used for cellular adhesion.
They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells.
They are substantially longer than flagella and are less common than flagella in human cells.
They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells.
You are explaining the causes of smoker’s cough to a client, including altered function of the cilia in the lining of large respiratory passages. Which of these is true?
Smoking causes the cilia to produce more mucus, resulting in coughing.
Smoking damages the cilia, rendering them unable to sweep mucus out of the respiratory passages, resulting in coughing.
Toxins in cigarette smoke irritate nerves under the cilia, causing a cough.
Cigarette smoke causes an overgrowth of cilia, leading to cough.
Smoking damages the cilia, rendering them unable to sweep mucus out of the respiratory passages, resulting in coughing.
Which of the following structures would aid a cell in allowing more nutrients to be absorbed by the cell?
microvilli
primary cilia
stereocilia
flagella
microvilli
The nucleolus __________.
is the site of ribosome subunit production in a cell
When a double helix of DNA is replicated, two complete helices are formed. Together, these helices are called sister __________.
chromatids
During which phase of mitosis do sister chromatids line up at the center of the cell?
Metaphase
During which phase of mitosis do the sister chromatids move apart?
Anaphase
During which phase of mitosis do nuclear envelopes and the nucleoli reappear?
Prophase
Telophase
During which phase of mitosis do the nuclear envelope and nucleoli disappear?
late Prophase
What is the name of the process by which the cytoplasm divides in two?
Cytokinesis
During which phase of the cell cycle does DNA duplication, or replication, take place?
Interphase
After DNA replication is completed, what does each DNA double helix consist of?
one old template strand and one new daughter strand
__________ is a molecule that brings amino acids to the ribosome during translation.
t-RNA
Apoptosis is programmed cell death; cancer cells do not undergo this process.
True
False
TRUE
