LATEST QUESTIONS AND
VERIFIED CORRECT
ANSWERS GRADED A+
List and give general function(s) of the major organic molecules found in the human body.
Name the building block of each (for lipid: name the building blocks of triglycerides). -
CORRECT ANSWER-1. Carbohydrates - monosaccharide (simple sugar)
2. Lipids - 1 glycerol + 3 fatty acids
3. Proteins - amino acids
4. Nucleic acids - nucleotides (sugar molecule + phosphate + nitrogenous base)
Name the high-energy molecule that cells utilize. Describe how energy is released from this
molecule. - CORRECT ANSWER-Adenosine triphosphate (ATP)
The third phosphate group is broken off, forming adenosine diphosphate (ADP) and converting
the stored energy from that bond into kinetic energy.
Define enzyme. - CORRECT ANSWER-A globular protein that acts as a biological catalyst
(increases the rates of chemical reactions within the body)
Define substrate. - CORRECT ANSWER-The substance that an enzyme acts on
,Differentiate between RNA and DNA. Name the monosaccharide found in RNA and name the
monosaccharide found in DNA. List the nitrogenous bases found in RNA and in DNA. -
CORRECT ANSWER-RNA: ribonucleic acid - functions in protein synthesis,
monosaccharide is ribose, nitrogenous bases are adenine, guanine, cytosine, and uracil
DNA: deoxyribonucleic acid - hereditary material of cells, monosaccharide is deoxyribose,
nitrogenous bases are adenine, guanine, cytosine, and thymine
Define cell. - CORRECT ANSWER-The smallest unit of life
Describe the structure of the plasma membrane. - CORRECT ANSWER-Structurally, the
plasma membrane is a phospholipid bilayer. Glycerol phosphate groups lie on the inside and
outside of the plasma membrane, and between these, 2 fatty acids are attached to each
glycerol head.
Define selectively permeable. - CORRECT ANSWER-Having the ability to select what can
enter and exit
Define simple diffusion. - CORRECT ANSWER-Passive transport process that involves the
transport of substances from high concentration to low concentration (down concentration
gradient)
Define facilitated diffusion. - CORRECT ANSWER-Substances are transported either by
binding to carrier proteins (which ferry the substance cross the plasma membrane) or by
moving through channel proteins
Define concentration gradient. - CORRECT ANSWER-A situation that occurs when the
concentration of a solute is higher in one area than in another
,Define osmosis. - CORRECT ANSWER-Diffusion of water through a selectively permeable
membrane
Define solute. - CORRECT ANSWER-The substance in a mixture that is in lower
concentration - there is often more than one
Define solvent. - CORRECT ANSWER-The substance in a mixture that is in higher
concentration - there is only ever one, usually water
Define osmotic pressure. - CORRECT ANSWER-The tendency of water to move into the
cell via osmosis
Define hydrostatic pressure. - CORRECT ANSWER-The pressure a fluid exerts on its
container
Define filtration. - CORRECT ANSWER-Substances move from an area of high hydrostatic
pressure to an area of low hydrostatic pressure, does not require the breakdown of ATP
Define active transport. - CORRECT ANSWER-Transport process that requires the
breakdown of ATP in order to utilize the released energy to move substances in or out of the
cell. Net movement is often from low concentration to high (against concentration gradient).
Define exocytosis. - CORRECT ANSWER-Active transport process that involves the
transport of substances outside the cell - secretory vesicles carrying substances fuse with the
plasma membrane and rupture, releasing the substances to the outside of the cell.
, Define endocytosis. - CORRECT ANSWER-Active transport process that involves the
transport of substances inside the cell
Define gap junction. - CORRECT ANSWER-Impermeable cell junction where there are
spaces in the plasma membranes between cells, allowing mostly ions to move between cells.
Define desmosome. - CORRECT ANSWER-Cell junction where cells are held together like
Velcro so they don't separate.
Define tight junction. - CORRECT ANSWER-Impermeable cell junction where cells are held
tightly together.
Explain what it means if a substance moves down its concentration gradient. - CORRECT
ANSWER-Substances move down their concentration gradients when they move from high
concentration to low. This does not require energy.
Explain what it means if a substance moves up its concentration gradient. - CORRECT
ANSWER-Substances move up their concentration gradients when they move from low
concentration to high. This requires energy (i.e. breakdown of ATP).
Differentiate between isotonic, hypertonic, and hypotonic solutions. - CORRECT ANSWER-
Isotonic: equal solute concentration, equal osmotic pressure, no net movement of water
Hypertonic: higher solute concentration and higher osmotic pressure than inside the cell, net
movement of water out of the cell
Hypotonic: lower solute concentration and lower osmotic pressure than inside the cell, net
movement of water into the cell