The Cell Flashcards
98% of the cell membrane is made up of lipids. Of those lipids, 75% are _________, 20% are _________, and 5% are _________.
phospholipids; cholesterol; glycolipids
Proteins in the cell membrane that open and close to allow ions into or out of the cell are called
ion channels
Proteins in the cell membrane that receive signals from other cells are called
receptors
Proteins in the cell membrane that allow the immune system to identify a cell as one of your own cells (and not attack it) are called
cell identity markers
Proteins in the cell membrane that allow cells to bind to each other are called
cell adhesion molecules
Proteins in the cell membrane that break down messenger molecules (so that they don’t keep signaling the cells) are a type of
enzymes
The plasma membrane is selectively permeable. What does this mean?
only certain substances can pass through it
When particles are driven through a membrane by the hydrostatic pressure of water, as in human capillaries and parts of the kidneys, it is called
filtration
Which of the following factors does NOT affect the rate of diffusion through a membrane?
temperature
the permeability of the membrane
the size of the molecules
the amount of ATP available
steepness of the concentration gradient
surface area of the membrane
the amount of ATP available
When water passes through a membrane due to the relative concentrations of water molecules, the process is called
osmosis
If a solution with a higher concentration of non-permeating particles, such as salt water, is added to human body tissues, that solution is considered to be ____________ to human cells. and will cause the cells to ____________.
hypertonic; crenate (shrink)
If distilled water (100% pure water) is added to human body tissues, that solution is considered to be ____________ to human cells. and will cause the cells to ____________.
hypotonic; burst
A ___________ membrane carrier carries only one solute at a time, while a __________ carrier carries 2 solutes in the same direction, and a __________ carrier carries 2 solutes in opposite directions.
uniport; symport; antiport
Which of the following is true of active transport?
it requires a carrier protein
it forces molecules against their concentration gradient
it requires energy in the form of ATP
all of the above are true of active transport
Which of the following is NOT true of the sodium-potassium pump?
the gradient it creates can be used to transport other molecules without utilizing additional energy
it helps to regulate cell osmolarity and volume
it pumps 2 sodium into the cell and 3 potassium out of the cell
it maintains a resting membrane potential for cells to generate electricity
it can be used to produce heat to help maintain body temperature
it pumps 2 sodium into the cell and 3 potassium out of the cell
The form of vesicular transport that is sometimes called “cell eating” because large particles are engulfed is actually called
phagocytosis
The form of vesicular transport that cells use to expel waste is called
exocytosis
Using vesicular transport to move substance into one side of a cell, transport it across the cell, and then release it out of the other side of the cell is called
transcytosis
Which of the following is NOT a membrane-bound organelle?
ribosome
A cell that specializes in producing and releasing proteins would be expected to have an unusually high amount of
rough endoplasmic reticulum
Cells that have very high energy requirements would be expected to have a high number of __________ in order to be able to meet those energy requirements.
mitochondria
Non-motile cilia are important for ____________, while motile cilia are important for ___________.
taking in sensory info; moving substances across the surface of the cells
When looking at the cytoskeleton of the cell, the __________ are important in maintaining a cell’s shape, while __________ are important in muscle contraction and cleavage, and ___________ are important for protecting cells from being torn apart.
microtubules; microfilaments; intermediate filaments
Which of the following is NOT one of the nitrogenous bases found in DNA?
Uracil (U)
When a cell activates the genes it needs to develop into a specialized, mature cell, the process is called
differentiation
Stem cells that can differentiate into most, but not all types of cells are called
pluripotent
When DNA is wrapped around histones to make it 1000x shorter and protect it from breakage, it is called
chromatin
Which of the following shows the stages of DNA Replication in the correct order?
Initiation -> Elongation -> Termination
In order for DNA replication to occur, ___________ must unzip the DNA to expose the bases, and __________ must attach the bases together to form the new DNA strand.
helicase; DNA polymerase
When a gene is ___________, it is turned on to make the protein that it codes for.
expressed
Amino acids in a protein are coded for by sequences of __ bases called ____________.
3; codons
_________ RNA carries the genetic information from the nucleus to the ribosomes, while _________ RNA delivers the amino acids to the ribosomes for assembly, and _________ RNA comes together to form the ribosomes.
messenger; transfer; ribosomal
Copying genetic instructions from the DNA to the RNA is called ___________, while converting the genetic information from mRNA to the amino acid sequence of a protein is called ___________.
transcription; translation
The molecule that elongates the mRNA during transcription is called
RNA Polymerase
The part of a tRNA molecule that binds to a complementary mRNA codon is called a(n) __________
anticodon
Cells accumulate the necessary resources and replicate DNA for mitosis during ___________.
interphase
Which of the following is NOT a function of mitosis?
replacement of cells that have died
repair of damaged tissues
growth of organs and tissues
creating gametes (egg and sperm cells)
creating gametes (egg and sperm cells)
During mitosis, chromosomes line up in the middle of the cell during ____________, and are pulled away from each other to opposite sides of the cell during ____________.
metaphase; anaphase
Which of the following conditions must be met for mitosis to move forward under normal circumstances?
There must be enough cytoplasm for 2 daughter cells
DNA replication must be complete
There must be enough nutrients for the process to occur
The chromosomes must be in the correct positions during each phase
All of the above conditions must be met for mitosis to move forward
If there are not enough nutrients, growth factors, or space for new cells, then
mitosis will stop
Which of the following best describes cancer?
cancer is when your own cells get mutated and enter an unregulated state of mitosis
