BIOL 250 Exam 2 UPDATED ACTUAL Questions and CORRECT
Answers
Which elements are macronutrients/ What are the 6 Carbon, Hydrogen, Oxygens, Nitrogen, Phosphorous
elements that make up most of the mass of living
organisms?
What is the building block (monomer) of carbohydrates? monosaccharides
What constitutes an organic molecule? contains carbon and hydrogen
What is the name for molecules with both a hydrophilic amphipathic
group and a hydrophobic group?
What determines the function of biomolecules? structure
A primary proteins structure is a sequence of amino acids
A secondary protein structure is the local folding of the polypeptide chain into helices or sheets
Tertiary protein structure is: three-dimensional folding pattern of a protein due to side chain interactions
Quaternary protein structure is___ _. protein consisting of more than one amino acid chain
What does it mean to denature a protein? changing its shape which in turn changes its functions; this could be through pH
or chemicals
What is anabolism? small molecules assembled into macromolecules
What is catabolism? breaking down molecules and releasing energy (like a cat knocking stuff down)
What is the function of an electron carrier? shuttles electrons between compounds in metabolic pathway
What is the "energy currency" of the cell? ATP is the energy currency (like dollars) and electrons are a small part (like
change)
What is activation energy? energy needed to start a reaction
What is a catalyst's effect on activation energy? Catalysts lower the activation energy for a chemical reaction
What is the role of cofactors? stabilize enzyme conformation (structure) and function
What are coenzymes? organic molecules required for enzyme actions
What are the different forms of enzyme inhibitors? competitive inhibitors and allosteric inhibitors (non-competitive)
, Can glycolysis be performed by obligate aerobes, both obligate aerobes and obligate anaerobes
obligate anaerobes, or both?
Aerobic respiration is Respiration that requires oxygen and has high ATP yield
Anaerobic respiration is respiration that does not require oxygens and has a lower ATP yield
Why does fermented foods taste sour? Bacteria performs lactic acid fermentation; this production of acid registers as
sour in taste
What enzymes break down lipids? lipase
What enzyme breaks down phospholipids? phospholipase
Why would enzymes used to break down proteins need they are too large to enter the cell directly, they have to break down outside the
to be extracellular? cell into smaller peptides so the cell can absorb them
What type of molecules absorb light in photosynthetic pigments
organisms?
What did many anaerobic bacteria die after cyanobacteria produced oxygen through photosynthesis
cyanobacteria evolved?
Why are nitrogen fixing bacteria important for plants? They fix the 78% nitrogen that plants cannot use and converts it into ammonia
(NH3) which plants can absorb and use to build essential molecules
Why do bacteria and viruses make good model systems their DNA, is small flexible and easy to manipulate
for genetic studies?
Why does DNA with higher GC content denature at a G-C has more hydrogen bonds making them stronger than A-T pairing with fewer
higher temperature than DNA with higher AT content? hydrogen bonds
What is tRNA role in protein synthesis? transfers/brings the correct amino acid to the site of protein synthesis in the
ribosome
What is mRNA role in protein synthesis? Carries the message from DNA when a certain protein is needed
What is rRNA role in protein synthesis? ensures proper alignment of mRNA, tRNA, and ribosomes; catalyses the
formation of peptide bonds between amino acids
What does it mean when base composition of base pairs it is single stranded DNA
does not match? If A (15%), C(20%), G(30%), and T(35%)
If it contained U, then it would be RNA
A certain DNA sample is found to have a makeup A(22%), C(28%), G(28%)
consisting of 22% thymine? What is the percentage of
A,C, and G?
What are prokaryotic chromosomal structures like? singular linear chromosome, single copy of each gene (haploid), DNA gyrase is a
topoisomerase unique to prokaryotes
Answers
Which elements are macronutrients/ What are the 6 Carbon, Hydrogen, Oxygens, Nitrogen, Phosphorous
elements that make up most of the mass of living
organisms?
What is the building block (monomer) of carbohydrates? monosaccharides
What constitutes an organic molecule? contains carbon and hydrogen
What is the name for molecules with both a hydrophilic amphipathic
group and a hydrophobic group?
What determines the function of biomolecules? structure
A primary proteins structure is a sequence of amino acids
A secondary protein structure is the local folding of the polypeptide chain into helices or sheets
Tertiary protein structure is: three-dimensional folding pattern of a protein due to side chain interactions
Quaternary protein structure is___ _. protein consisting of more than one amino acid chain
What does it mean to denature a protein? changing its shape which in turn changes its functions; this could be through pH
or chemicals
What is anabolism? small molecules assembled into macromolecules
What is catabolism? breaking down molecules and releasing energy (like a cat knocking stuff down)
What is the function of an electron carrier? shuttles electrons between compounds in metabolic pathway
What is the "energy currency" of the cell? ATP is the energy currency (like dollars) and electrons are a small part (like
change)
What is activation energy? energy needed to start a reaction
What is a catalyst's effect on activation energy? Catalysts lower the activation energy for a chemical reaction
What is the role of cofactors? stabilize enzyme conformation (structure) and function
What are coenzymes? organic molecules required for enzyme actions
What are the different forms of enzyme inhibitors? competitive inhibitors and allosteric inhibitors (non-competitive)
, Can glycolysis be performed by obligate aerobes, both obligate aerobes and obligate anaerobes
obligate anaerobes, or both?
Aerobic respiration is Respiration that requires oxygen and has high ATP yield
Anaerobic respiration is respiration that does not require oxygens and has a lower ATP yield
Why does fermented foods taste sour? Bacteria performs lactic acid fermentation; this production of acid registers as
sour in taste
What enzymes break down lipids? lipase
What enzyme breaks down phospholipids? phospholipase
Why would enzymes used to break down proteins need they are too large to enter the cell directly, they have to break down outside the
to be extracellular? cell into smaller peptides so the cell can absorb them
What type of molecules absorb light in photosynthetic pigments
organisms?
What did many anaerobic bacteria die after cyanobacteria produced oxygen through photosynthesis
cyanobacteria evolved?
Why are nitrogen fixing bacteria important for plants? They fix the 78% nitrogen that plants cannot use and converts it into ammonia
(NH3) which plants can absorb and use to build essential molecules
Why do bacteria and viruses make good model systems their DNA, is small flexible and easy to manipulate
for genetic studies?
Why does DNA with higher GC content denature at a G-C has more hydrogen bonds making them stronger than A-T pairing with fewer
higher temperature than DNA with higher AT content? hydrogen bonds
What is tRNA role in protein synthesis? transfers/brings the correct amino acid to the site of protein synthesis in the
ribosome
What is mRNA role in protein synthesis? Carries the message from DNA when a certain protein is needed
What is rRNA role in protein synthesis? ensures proper alignment of mRNA, tRNA, and ribosomes; catalyses the
formation of peptide bonds between amino acids
What does it mean when base composition of base pairs it is single stranded DNA
does not match? If A (15%), C(20%), G(30%), and T(35%)
If it contained U, then it would be RNA
A certain DNA sample is found to have a makeup A(22%), C(28%), G(28%)
consisting of 22% thymine? What is the percentage of
A,C, and G?
What are prokaryotic chromosomal structures like? singular linear chromosome, single copy of each gene (haploid), DNA gyrase is a
topoisomerase unique to prokaryotes
