Chapter 3 Flashcards
What is the cell membrane?
The extremely pliable structure composed primarily of back-to-back phospholipids that encloses a cell.
What is hydrophilic?
Attracted to water. Polar.
What is hydrophobic?
Repels and is repelled by water. Nonpolar.
What is amphipathic?
A molecule that contains both a hydrophobic and hydrophilic region. Hydrophilic portion can dissolve in water and the hydrophobic region can trap oil.
What is intracellular fluid?
Fluid interior of the cell
What is extracellular fluid?
Fluid environment outside the enclosure of the cell membrane
What is interstitial fluid?
Extracellular fluid not contained within blood vessels
What is the phospholipid bilayer?
Consists of two adjacent sheets of phospholipids arranged tail to tail. Hydrophobic tails associate with one another and form the interior of the membrane. Polar heads contact the fluid outside and inside of the cell
What is a phospholipid?
Molecule that consists of a polar, hydrophilic phosphate head (phosphate + glycerol) and a nonpolar hydrophobic lipid tail (unsaturated fatty acid and saturated fatty acid). Unsaturated fatty acids result in kinks in the tail.
What is an integral protein?
A protein that is embedded in the cell membrane
What is a channel protein?
An integral protein that selectively allows particular materials to pass in and out of the cell through the cell membrane.
What is a glycoprotein?
A protein with a carbohydrate attached
What is a glycolipid?
A lipid with a carbohydrate attached
What is a peripheral membrane protein?
A protein that is typically found on the inner or outer surface of the lipid bilayer but can also be attached to the internal or external surface as an integral protein.
What is selective permeability?
Only allows substances meeting a certain criteria to pass through a membrane unaided
What is passive transport?
The movement of substances across the membrane without the expenditure of cellular energy
What is active transport?
The movement of substances across the membrane using energy from ATP
What is a concentration gradient?
Difference in concentration of a substance across a space
What is diffusion?
The movement of particles from an area of higher concentration to an area of lower concentration - move down the concentration gradient
What is facilitated diffusion?
The diffusion process used for substances that cannot cross the lipid bilayer due to their size, charge, or polarity, through specific transmembrane proteins
What is simple diffusion?
The process by which molecules, atoms, or ions diffuse through a selectively permeable membrane down their concentration gradient without the assistance of transporter proteins
What is osmosis?
The diffusion of water through a semipermeable membrane. Occurs when there is an imbalance of solutes outside of a cell versus inside the cell
What is isotonic?
Two solutions that have the same concentration of solutes - “equal tension”
What is hypertonic?
A solution that has a higher concentration of solutes than another solution. Water molecules tend to diffuse into.
What is hypotonic?
A solution that has a lower concentration of solutes than another solution. Water molecules tend to diffuse out of.
What is anaphase?
third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell
What is an anticodon?
consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on an mRNA molecule
What is autolysis?
breakdown of cells by their own enzymatic action
What is autophagy?
lysosomal breakdown of a cell’s own components
What is the cell cycle?
life cycle of a single cell, from its birth until its division into two new daughter cells
What is the cell membrane?
membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various molecules; also known as plasma membrane
What is a centriole?
small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division
What is a centromere?
region of attachment for two sister chromatids
What is a centrosome?
cellular structure that organizes microtubules during cell division
What is a channel protein?
membrane-spanning protein that has an inner pore which allows the passage of one or more substances
What is a checkpoint?
progress point in the cell cycle during which certain conditions must be met in order for the cell to proceed to a subsequence phase
What is chromatin?
substance consisting of DNA and associated proteins
What is a chromosome?
condensed version of chromatin
What are cilia?
small appendage on certain cells formed by microtubules and modified for movement of materials across the cellular surface
What is the cleavage furrow?
contractile ring that forms around a cell during cytokinesis that pinches the cell into two halves
What is a codon?
consecutive sequence of three nucleotides on an mRNA molecule that corresponds to a specific amino acid
What is cyclin?
one of a group of proteins that function in the progression of the cell cycle
What is cyclin-dependent kinase (CDK)?
one of a group of enzymes associated with cyclins that help them perform their functions
What is cytokinesis?
final stage in cell division, where the cytoplasm divides to form two separate daughter cells
What is the cytoplasm?
internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called cytosol, within which are all the other organelles and cellular solute and suspended materials
What is the cytoskeleton?
“skeleton” of a cell; formed by rod-like proteins that support the cell’s shape and provide, among other functions, locomotive abilities
What is cytosol?
clear, semi-fluid medium of the cytoplasm, made up mostly of water
What is a diploid?
condition marked by the presence of a double complement of genetic material (two sets of chromosomes, one set inherited from each of two parents)
What is DNA polymerase?
enzyme that functions in adding new nucleotides to a growing strand of DNA during DNA replication
What is DNA replication?
process of duplicating a molecule of DNA
What is the electrical gradient?
difference in electrical charge across a space.