bio test 2 hw questions
How many hydrogen atoms can be attached to carbon B? A model of molecule with a chain of four carbon atoms. There is a double bond between the second and third carbons.
1
What is the maximum number of moles of glycine (C2H5NO2) that could be made in the flask if no other molecules were made?
1 mole of glycine
For every 1.0 mole of glycine in the sample, how many molecules of methionine are present?
1.08 × 10^21 molecules of methionine
Polymers that contain sugars ...
(a) may store hereditary information. (b) may store energy. (c) may protect cells.
Triglycerides vary with respect to the number of ...
(b) C atoms in the tails. (c) double bonds in the tails.
A mole (abbreviated mol) is defined as an exact number of objects: 6.02 × 1023 (Avogadro's number). You can have 1 mole of an atom, a molecule, or any other object, such as eggs or books. One mole of an object equals 6.02 × 1023 of that object. The table shows the "molar ratios" of some of the products from the Miller H2S experiment. In a molar ratio, each unitless value is expressed relative to a standard for that experiment. Here, the standard is the number of moles of the amino acid glycine, which is set to a value of 1.0. For instance, serine has a molar ratio of 3.0 × 10-2, meaning that for every mole of glycine, there is 3.0 × 10-2 mole of serine present in the sample. What is the molar ratio of methionine to glycine in the samples?
1.8 × 10-3 mole of methionine per mole of glycine
How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule?
19
Glycine's molecular formula is C2H5NO2. How many moles of each element would be needed to make 1.0 mole of glycine?
2 moles carbon, 5 moles hydrogen, 1 mole nitrogen, and 2 moles oxygen
What is the maximum number of moles of serine that could be made in the flask if no other molecules were made?
2/3 (0.67) of a mole of serine
What is the maximum number of moles of methionine that could be made in the flask if no other molecules were made?
2/5 (0.4) of a mole of methionine
How many electrons does one atom of carbon share to complete its valence shell?
4
How many molecules of glycine are present in 1.0 mole of glycine?
6.02 × 10^23 molecules
If there is 1.0 mole of glycine present in the sample, how many more molecules of alanine are present?
6.02x10^22
Use the figures to answer the question. Four functional groups labeled from A to D. Group A is OH. Group B is COOH with an oxygen double-bonded to the carbon atom. Group C is NH2. Group D is SH. Which of the functional groups shown is present in ethanol but not in ethane?
A
Identify the functional groups.
Amino and carboxyl are functional groups.
Use the figures to answer the question. Four chemical compounds labeled from A to D. Compound A is CH3CHO with an O atom double-bonded to the second (from left to right) carbon atom. Compound B is CH3COCH3 with an O atom double-bonded to the second (from left to right) carbon atom. Compound C is CH3COOH with an O atom double-bonded to the second (from left to right) carbon atom. Compound D is CH3NH2. Which molecule shown can increase the concentration of hydrogen ions in a solution and is therefore an organic acid?
C
Use the figures to answer the question. Four cemical compounds labeled from A to D. Compound A is CH3CHO with an O atom double-bonded to the second (from left to right) carbon atom. Compound B is CH3COCH3 with an O atom double-bonded to the second (from left to right) carbon atom. Compound C is CH3COOH with an O atom double-bonded to the second (from left to right) carbon atom. Compound D is CH3NH2. Which molecule(s) shown is (are) ionized in a cell?
C and D
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
C18H32O16
Which of the following is a hydrocarbon?
C3H8
Use the figures to answer the question. Four chemical compounds labeled from A to D. Compound A is CH3NH2. Compound B is CH3SH. Compound C is CH3CH2CHO with an O atom double-bonded to the third (from left to right) carbon atom. Compound D is CH3OPO3. Two oxygen atoms that are attached to the phosphorous atom are negatively charged. Which molecule shown above contains a functional group that is a part of the molecule known as the "energy currency of living organisms"?
D
Use the figures to answer the question. Four functional groups labeled from A to D. Group A is OH. Group B is COOH with an oxygen double-bonded to the carbon atom. Group C is NH2. Group D is SH. Which of the functional groups shown helps stabilize proteins by forming covalent cross-links within or between protein molecules?
D
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart.
Which of the following is true of carbon?
It can form both polar and nonpolar bonds.
Which of the following statements about monosaccharide structure is true?
Monosaccharides can be classified according to the spatial arrangement of their atoms.
L-dopa is used to treat _____.
Parkinson's disease
Match the monomers with their polymers.
Protein polymers are made up of -amino acid- monomers. Carbohydrate polymers are made up of -simple sugar- monomers. Nucleic acid polymers are made up of -nucleotide- monomers.
Which of these is NOT a lipid?
RNA
Which of the functional groups shown above is most likely to gain a proton and become positively charged?
The amino group is most likely to gain a proton
Why are hydrocarbons insoluble in water?
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
How do phospholipids interact with water molecules?
The polar heads interact with water; the nonpolar tails do not.
What do DNA, proteins, and fats have in common?
They contain carbonyl groups.
For lipids to be fluid at room temperature, they should have ________.
a higher number of cis double bonds
Glycogen is _____.
a polysaccharide found in animals
The presence of many C-C and C-H bonds causes fats to be ...
a) rich in energy. (b) insoluble in water
Which amino acid is present in higher amounts than glycine in the samples?
alanine
Which complex carbohydrate contains only a-1,4-glycosidic linkages?
amylose
Enantiomers are molecules that _____.
are mirror images
Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that _____.
are mirror images of each other
Starch and cellulose ________.
are polymers of glucose
A function of cholesterol that does not harm health is its role _____.
as a component of animal cell membranes
Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a hydrocarbon chain with the same number of carbon atoms, but with one or more double bonds, will _____.
be more constrained in structure
Which of the following could be responsible for atherosclerosis and should be eliminated from diet for health reasons?
butter and lard
If only methionine (C5H11NO2S) was made, which element would be used up first?
carbon
If only serine (C3H7NO3) was made, which element would be used up first in the flask?
carbon
The element present in all organic molecules is _____.
carbon
What does the term insoluble fiber refer to on food packages?
cellulose
Which of these is a polysaccharide?
cellulose
_____ is the most abundant organic compound on Earth.
cellulose
Which of the following complex carbohydrates is listed with its correct function?
cellulose: structural component of plant cell walls
Use the following figure to answer the question. Two structures with a CC double bond. The first (from left to right) carbon of the first structure has a CH3 group attached above and an H atom attached below the plane of the bond. The other carbon has a CH3 group attached above and an H atom attached below the plane of the bond. The first (from left to right) carbon of the second structure has an H atom attached above and a CH3 group attached below. The other carbon has a CH3 group attached above and an H atom attached below the plane of the bond. The two molecules shown in the figure are best described as ________.
cis-trans isomers
What is another name for a condensation reaction?
dehydration
Cis-trans isomers (geometric isomers) are molecules that _____.
differ in the arrangement of their atoms about a double bond
Which of the following is not a polymer?
glucose
In fat synthesis,________and fatty acids combine to make fats plus________.
glycerol; water
A carbon atom has 6 electrons however, its valency is 4. This is because the carbon atom ________.
has only 2 electrons in its first shell and 4 in the second shell
Phospholipids and triglycerides both _____.
have a glycerol backbone
Humans can digest starch but not cellulose because ________.
humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose
What is the name of the process during which a bond between two monomers is broken?
hydrolysis
In the reaction that builds a fat,________ groups react with ________ groups.
hydroxyl; carboxyl
An atom of iron has the atomic number 26. This means that
it has 26 protons and 26 electrons
The kind and number of bonds an atom can form depends on ________.
its electron configuration
Which molecule is not a carbohydrate?
lipid
A food company hydrogenated a barrel of fat. The treatment ...
made the fat less fluid.
glucose + glucose —> _____ by _____.
maltose + water ... dehydration synthesis
Which of the compounds shown in the data table in Figure 1 could be made in the H2S experiment but could not be made in the earlier experiment (Figure 3)?
methionine
Which of these is a source of lactose?
milk
A molecule with the chemical formula C6H12O6 is probably a _____.
monosaccharide
What kind of effect does R-dopa have on Parkinson's disease?
none
Which of these is rich in unsaturated fats?
olive oil
Stanley Miller's 1953 experiments supported the hypothesis that _____.
organic molecules can be synthesized abiotically under conditions that may have existed on early Earth
Miller's classic experiment demonstrated that a discharge of sparks through a mixture of gases could result in the formation of a large variety of organic compounds. Miller did not use ________ as one of the gases in his experiment.
oxygen
Which polysaccharide contains a modified monosaccharide?
peptidoglycan
What makes lipids/fats hydrophobic?
presence of relatively nonpolar CH bonds
An atom has four electrons in its valence shell. What type(s) of covalent bonds is it capable of forming with oxygen?
single and double bonds
Use the following figure to answer the question. There is a molecule with five fused six-carbon rings and a tail. Carbon atoms are numerated clockwise starting from the carbon at the top of the ring. The second and the third carbons of ring 1 are common with the fifth and the sixth carbons of ring 2. The first and the second carbons of ring 2 are common with the fourth and the fifth carbons of ring 3. The second and the third carbons of ring 3 are common with the fifth and the sixth carbons of ring 4. The first and the second carbons of ring 4 are common with the fourth and the fifth carbons of ring 5. A CH3 group is attached to the second carbon of ring 1. An OH group is attached to the fifth carbon of ring 1. The fourth and the fifth carbons of ring 2 are double-bonded. A CH3 group is attached to the second carbon of ring 2. A CH3 group is attached to the sixth carbon of ring 5. CH2CH2CH2CHCH3CH3 is attached to the second carbon of ring 5. The molecule shown the figure is a ________.
steroid
These molecules are _____.
structural isomers
Based on the electron configuration of the elements below, which would exhibit a chemical behavior most like that of oxygen? 126C168O11H147N3216S3115P, where the upper index is atomic mass and the lower index is atomic number.
sulfur
The complexity and variety of organic molecules is due to _____.
the chemical versatility of carbon atoms
The most unsaturated fats have ...
the most double bonds
What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration?
the presence or absence of double bonds between the carbon atom and other atoms
People who are lactose intolerant cannot extract energy from milk because ________.
they are missing an enzyme
True or false? Peptidoglycan is a polysaccharide found only in bacteria.
true
Each double bond in carbon dioxide represents ________.
two pairs of shared electrons
A dehydration reaction (or condensation reaction) is the process in which _____.
water molecules are produced as a polymer is formed from monomers
Use the following figure to answer the question. CH3CH2CHCHCH2CH2CH2CHCHCH2COH with a double bond between the third (from left to right) and the fourth carbon atoms and between the eighth and the ninth carbon atoms. An oxygen atom is double bonded to the eleventh carbon atom. The molecule illustrated in the figure ________.
will be liquid at room temperature
