BIOL 1500 EXAM #2 QUESTIONS AND
ANSWERS
extracellular matrix - ANSWER-The substance in which animal tissue cells are
embedded, consisting of protein and polysaccharides.
Plasmodesmata - ANSWER-channels through cell walls that connect the cytoplasms
of adjacent cells
tight junctions - ANSWER-Membranes of neighboring cells are pressed together,
preventing leakage of extracellular fluid
Desmosomes - ANSWER-fasten cells together into strong sheets; prevent cells from
separating during contraction
gap junctions - ANSWER-provide cytoplasmic channels between adjacent animal
cells
What does the fluid mosaic model depict? - ANSWER-membrane as a mosaic of
protein molecules bobbing in a fluid bilayer of phospholipids
what holds membranes together - ANSWER-weak hydrophobic interactions
peripheral proteins - ANSWER-bound to the surface of the membrane
function of integral proteins - ANSWER-penetrate the hydrophobic core
transmembrane proteins - ANSWER-Integral proteins that span the membrane.
What are glycolipids? - ANSWER-carbohydrates attached to lipids
What are glycoproteins? - ANSWER-carbs bonded to proteins
what greatly increases rate of pasage - ANSWER-aquaporins
What is tonicity? - ANSWER-the ability of a surrounding solution to cause a cell to
gain or lose water
What is an isotonic solution? - ANSWER-Contains equal concentratinos of solutes
on both sides.
What is a hypertonic solution? - ANSWER-Solute concentration is greater than that
inside the cell; cell loses water
What are peroxisomes? - ANSWER-specialized metabolic compartments bounded
by a single membrane
, function of peroxisomes - ANSWER-break down fatty acids; enzymes remove
hydrogen and transfer them to oxygen
function of cytoskeleton - ANSWER-Helps cell maintain shape and helps the cell
move
function of microtubules - ANSWER-Shaping the cell;
Guiding movement of organelles;
Separating chromosomes during cell division
What are centrosomes? - ANSWER-Microtubule-organizing centers that help to form
and organize the mitotic spindle during mitosis
What are centrioles? - ANSWER-Centrioles help organize cell division and are
formed from tubulin and located near the nucleus.
What are microfilaments? - ANSWER-threadlike structures made up of a protein
called actin
function of microfilaments - ANSWER-assist with cell movement
describe primary cell wall - ANSWER-relatively thin and flexible
describe function of middle lamella - ANSWER-Cements adjoining cells together
using pectin- needed for stability
function of secondary cell wall - ANSWER-Adds strength
what is a hypotonic solution? - ANSWER-Solute concentration is less than that
inside the cell; cell gains water
What is osmoregulation? - ANSWER-the control of solute concentrations and water
balance
What is plasmolysis? - ANSWER-Shrinkage of a cell due to water being removed
due to a hypertonic solution.
What is membrane potential? - ANSWER-a voltage or electrical charge across the
plasma membrane
what is an electrogenic pump - ANSWER-a transport protein that generates voltage
across a membrane
function of electrogenic pump - ANSWER-stores energy for cellular work
which pump do animals use - ANSWER-sodium-potassium pump
which pump do plants, fungi, and bacteria use - ANSWER-proton pump
ANSWERS
extracellular matrix - ANSWER-The substance in which animal tissue cells are
embedded, consisting of protein and polysaccharides.
Plasmodesmata - ANSWER-channels through cell walls that connect the cytoplasms
of adjacent cells
tight junctions - ANSWER-Membranes of neighboring cells are pressed together,
preventing leakage of extracellular fluid
Desmosomes - ANSWER-fasten cells together into strong sheets; prevent cells from
separating during contraction
gap junctions - ANSWER-provide cytoplasmic channels between adjacent animal
cells
What does the fluid mosaic model depict? - ANSWER-membrane as a mosaic of
protein molecules bobbing in a fluid bilayer of phospholipids
what holds membranes together - ANSWER-weak hydrophobic interactions
peripheral proteins - ANSWER-bound to the surface of the membrane
function of integral proteins - ANSWER-penetrate the hydrophobic core
transmembrane proteins - ANSWER-Integral proteins that span the membrane.
What are glycolipids? - ANSWER-carbohydrates attached to lipids
What are glycoproteins? - ANSWER-carbs bonded to proteins
what greatly increases rate of pasage - ANSWER-aquaporins
What is tonicity? - ANSWER-the ability of a surrounding solution to cause a cell to
gain or lose water
What is an isotonic solution? - ANSWER-Contains equal concentratinos of solutes
on both sides.
What is a hypertonic solution? - ANSWER-Solute concentration is greater than that
inside the cell; cell loses water
What are peroxisomes? - ANSWER-specialized metabolic compartments bounded
by a single membrane
, function of peroxisomes - ANSWER-break down fatty acids; enzymes remove
hydrogen and transfer them to oxygen
function of cytoskeleton - ANSWER-Helps cell maintain shape and helps the cell
move
function of microtubules - ANSWER-Shaping the cell;
Guiding movement of organelles;
Separating chromosomes during cell division
What are centrosomes? - ANSWER-Microtubule-organizing centers that help to form
and organize the mitotic spindle during mitosis
What are centrioles? - ANSWER-Centrioles help organize cell division and are
formed from tubulin and located near the nucleus.
What are microfilaments? - ANSWER-threadlike structures made up of a protein
called actin
function of microfilaments - ANSWER-assist with cell movement
describe primary cell wall - ANSWER-relatively thin and flexible
describe function of middle lamella - ANSWER-Cements adjoining cells together
using pectin- needed for stability
function of secondary cell wall - ANSWER-Adds strength
what is a hypotonic solution? - ANSWER-Solute concentration is less than that
inside the cell; cell gains water
What is osmoregulation? - ANSWER-the control of solute concentrations and water
balance
What is plasmolysis? - ANSWER-Shrinkage of a cell due to water being removed
due to a hypertonic solution.
What is membrane potential? - ANSWER-a voltage or electrical charge across the
plasma membrane
what is an electrogenic pump - ANSWER-a transport protein that generates voltage
across a membrane
function of electrogenic pump - ANSWER-stores energy for cellular work
which pump do animals use - ANSWER-sodium-potassium pump
which pump do plants, fungi, and bacteria use - ANSWER-proton pump
