BCH 361 EXAM 1 QUESTIONS WITH VERIFIED
ANSWERS
Carbohydrates, lipids, proteins, and nucleic acids - Answers - molecules seen in all
organisms
___ for life are encoded in nucleic acid - Answers - instructions
The ability to ____ is inherent for all organisms - Answers - reproduce
Eukaryotes - Answers - cell has nucleus
Prokaryotes - Answers - cell with no nucleus
Double-membrane bounded compartments in eukaryotic cells - Answers - nucleus,
mitochondrion, chloroplast
nucleus - Answers - location of main genome
site of most DNA and RNA synthesis
mitochondrion - Answers - site of energy-yielding oxidation reactions; has its own DNA
Chloroplast - Answers - Site of photosynthesis in green plants and algae; has its own
DNA
Endoplasmic reticulum - Answers - continuous membrane throughout the cell; rough
part studded with ribosomes (the site of protein synthesis)
Golgi Apparatus - Answers - series of flattened membranes; involved in secretion of
proteins from cells and in reactions that link sugars to other cellular components
lysosomes - Answers - membrane-enclosed sacs containing hydrolytic enzymes
peroxisomes - Answers - sacs that contain enzymes involved in the metabolism of
hydrogen peroxide
cell membrane - Answers - separates the cell contents from the outside world; contents
include organelles (held in place by the cytoskeleton) and the cytosol
cell wall - Answers - rigid exterior layer of plant cells
central vacuole - Answers - membrane-enclosed sac in plant cells
, Atomic composition of organisms - majority consists of four types of atoms - Answers -
hydrogen, oxygen, carbon, nitrogen
humans and most other organisms are ___ water - Answers - 70%
___ is by far the most abundant element (by mass) after taking out water, followed by
____ - Answers - C
N,O,H
The most abundant metal elements are - Answers - Ca, K, Na, Mg
Essential - Answers - P, S, Cl
Four major classes of molecules - Answers - proteins, nucleic acids, lipids,
carbohydrates
water is a ___ molecule - Answers - polar
Two H2O molecules are joined by a ___ bond - Answers - hydrogen
non-covalent interactions - Answers - ionic, hydrogen, van der Waals
hydrophobic effect - Answers - clustering of hydrophobic molecules in water; causes
phase separation; powerful organizing force in biological systems
Second law of thermodynamics - Answers - total entropy (randomness) of a system and
its surroundings always increases in a spontaneous process; order and organization
costs energy
hydrophobic effect is powered by - Answers - increase in the entropy of water that
results when hydrophobic molecules come together
acid - Answers - proton donor
base - Answers - proton acceptor
deprotonated form - Answers - pH is >1 pH unit greater than the pKa of functional group
protonated form - Answers - pH is >1 pH unit less than the pKa of functional group, then
buffers - Answers - compounds whose pKa is close to desired pH
stabilize pH by converting conjugate base to conjugate acid (or vice versa)
Isoelectric Point (pI) - Answers - pH where average charge is 0
midway between the two pKa values that indicate protonation and deprotonation
ANSWERS
Carbohydrates, lipids, proteins, and nucleic acids - Answers - molecules seen in all
organisms
___ for life are encoded in nucleic acid - Answers - instructions
The ability to ____ is inherent for all organisms - Answers - reproduce
Eukaryotes - Answers - cell has nucleus
Prokaryotes - Answers - cell with no nucleus
Double-membrane bounded compartments in eukaryotic cells - Answers - nucleus,
mitochondrion, chloroplast
nucleus - Answers - location of main genome
site of most DNA and RNA synthesis
mitochondrion - Answers - site of energy-yielding oxidation reactions; has its own DNA
Chloroplast - Answers - Site of photosynthesis in green plants and algae; has its own
DNA
Endoplasmic reticulum - Answers - continuous membrane throughout the cell; rough
part studded with ribosomes (the site of protein synthesis)
Golgi Apparatus - Answers - series of flattened membranes; involved in secretion of
proteins from cells and in reactions that link sugars to other cellular components
lysosomes - Answers - membrane-enclosed sacs containing hydrolytic enzymes
peroxisomes - Answers - sacs that contain enzymes involved in the metabolism of
hydrogen peroxide
cell membrane - Answers - separates the cell contents from the outside world; contents
include organelles (held in place by the cytoskeleton) and the cytosol
cell wall - Answers - rigid exterior layer of plant cells
central vacuole - Answers - membrane-enclosed sac in plant cells
, Atomic composition of organisms - majority consists of four types of atoms - Answers -
hydrogen, oxygen, carbon, nitrogen
humans and most other organisms are ___ water - Answers - 70%
___ is by far the most abundant element (by mass) after taking out water, followed by
____ - Answers - C
N,O,H
The most abundant metal elements are - Answers - Ca, K, Na, Mg
Essential - Answers - P, S, Cl
Four major classes of molecules - Answers - proteins, nucleic acids, lipids,
carbohydrates
water is a ___ molecule - Answers - polar
Two H2O molecules are joined by a ___ bond - Answers - hydrogen
non-covalent interactions - Answers - ionic, hydrogen, van der Waals
hydrophobic effect - Answers - clustering of hydrophobic molecules in water; causes
phase separation; powerful organizing force in biological systems
Second law of thermodynamics - Answers - total entropy (randomness) of a system and
its surroundings always increases in a spontaneous process; order and organization
costs energy
hydrophobic effect is powered by - Answers - increase in the entropy of water that
results when hydrophobic molecules come together
acid - Answers - proton donor
base - Answers - proton acceptor
deprotonated form - Answers - pH is >1 pH unit greater than the pKa of functional group
protonated form - Answers - pH is >1 pH unit less than the pKa of functional group, then
buffers - Answers - compounds whose pKa is close to desired pH
stabilize pH by converting conjugate base to conjugate acid (or vice versa)
Isoelectric Point (pI) - Answers - pH where average charge is 0
midway between the two pKa values that indicate protonation and deprotonation
