Unit II "Cells" Flashcards
hydrocarbons
contain only carbon and hydrogen atoms
what are the three categories of large biological molecules?
carbohydrates, proteins, and nucleic acids
polymers
large molecules made up of monomers
what is the process that cells use to link monomers into polymers?
dehydration synthesis
dehydration synthesis
chemical reaction that removes a molecule of water
what is the process that breaks down polymers?
hydrolysis
hydrolysis
breaks bonds between monomers by adding water to them
carbohydrates
class of molecules that include sugars and polymers
monosaccharides
monomers of carbohydrates
disaccharide
two monosaccharides linked by dehydration synthesis
polysaccharides
long chains of sugars
hydrophobic vs hydrophilic
water fearing vs water loving
do lipids fear water or do they mix well with water?
lipids are hydrophobic
protein
polymer of amino acid monomers
amino acid
central carbon atom bonded to four covalent partners
peptide bond
bond between adjacent amino acids
polypeptide
long chain of amino acids
cell theory
all living things the composed of cells and all cells come from other cells
what is the function of a plasma membrane?
regulates the traffic o molecules between the cell and its surroundings
what is the function of ribosomes?
build proteins according to instructions from the genes
what is the function of the nucleus? (what is it surrounded by?)
houses most of a eukaryotic cells’s DNA; surrounded by a double membrane
prokaryotes do not have a nucleus, but they do have a “nucleus-like” region called?
nucleoid (not partitioned from rest of cell)
what organelles do animal cells and plant cells NOT have in common? what functions do those organelles have?
plant cells: chloroplasts (perform photosynthesis)
animal cells: lysosomes (digestive enzymes)
phospholipids
two fatty acid tails along with a phosphate group
which parts of a phospholipid are hydrophobic and which are hydrophilic?
phosphate groups is hydrophilic; fatty acid tails are hydrophobic
chromatic
fibers made of long DNA molecules and associated proteins
what is the function of the nucleolus?
site where components of ribosomes are made
what are the functions of the rough ER?
multiple:
1) make more membrane
2) ribosomes attached to ER produce proteins which enter into the growing ER membrane, and then are transported to other organelles
transport vesicles
sacs made of membrane that bud off from the rough ER
what is the function of the smooth ER?
synthesis of lipids (including steroids)
what is the function of the golgi apparatus?
receives, refines, stores, and distributes chemical products of the cell
what is the function of the mitochondria?
harvests energy from sugars and other food molecules and uses it to produce another form of chemical energy called ATP
activation energy
activates the reactants and triggers chemical reactions
substrate
material upon which an enzyme acts
active site
region of the enzyme that has the shape and chemistry to fit the substrate molecule
diffusion
movement of molecules spreading out evenly onto the available space
semi-permeable
(cell membrane) only certain substances are allowed to pass
osmosis
diffusion of water across a selectively permeable membrane
plasmolysis
cells lose water in a hypertonic solution
hypertonic
solution with a higher concentration of solute
hypotonic
solution with a lower solute concentration
exocytosis
proteins exit the cell in transport vesicles that fuse with the membrane, spilling the contents outside the cell
endocytosis
cell takes material in via vesicles that bud inward
phagocytosis
cell engulfs a particle and packages it within a food vacuole
pinocytosis
cellular drinking
cell cycle
ordered sequence of events that extends from the time a cell is formed to the time it divides into two cells
interphase
time when cell performs its normal functions within the organism
mitosis
nucleus divides and contents are evenly distributed, forming two daughter nuclei
cytokinesis
cytoplasm is divided into two
interphase
chromosomes duplicate, copies remain attached to each other
prophase
chromosomes condense in nucleus and become visible. spindle forms in cytoplasm
prometaphase
nuclear membrane breaks, spindle starts to interact with chromosomes
metaphase
copied chromosomes align in the equator of the spindle
anaphase
chromosomes separate into two genetically identical groups and move to opposite sides of the spindle
telophase
nucleus membranes form around each set of chromosomes, spindle continues to break down
cell plate
appears in cytokinesis of a plant cell
