Unit 1 Review: The Chemistry of Life
What type of bond joins the molecules in a disaccharide?
A glycosidic bond.
The formula for glucose is C subscript 6, H subscript 12, O subscript 6. What type of sugar is glucose?
A hexose.
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
A hydrogen bond.
Which of the following is possible due to the surface tension of water?
A waterstrider can walk across a small pond.
Water is transported in plant tissues against gravity due to which of the following properties?
Adhesion, cohesion, & hydrogen bonding.
What are the monomers that make up proteins called?
Amino acids.
Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?
An amino acid such a glycine.
Observe the structures of glucose and fructose in Figure 4.2. These two molecules differ in the...?
Arrangement of carbon, hydrogen, and oxygen atoms.
The ionic bond of sodium chloride is formed when...?
Chlorine gains an electron from sodium.
The two molecules shown in Figure 4.1 are best described as...?
Structural isomers.
Which of the following is a function of proteins in cells?
Structure.
Which of the following characteristics is NOT true for saturated fats?
They tend to dissolve in water easily.
Which of the following statements is true?
To be enantiomers, a molecule must have at least four different atoms or groups connected to a central carbon.
What is the maximum number of atoms or molecules a single carbon atom can bond with?
Four atoms or molecules.
How many electron pairs does carbon share in order to complete its valence shell?
Four.
What is an example of a monosaccharide?
Fructose.
The two molecules shown in Figure 4.3 are best described as...?
Geometric isomers.
Which molecule contains a functional group known as an amino acid?
H-N-H (diagonal bonds) attached
Which of the following represents a polar covalent bond?
H-O
Which type of bond exemplifies a weak chemical bond?
Hydrogen bond.
Ice is lighter and floats in water because it is a crystalline structure held together by...?
Hydrogen bonds only.
Why does ice float in liquid water?
Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.
Which type of bond must be broken for water to vaporize?
Hydrogen bonds.
________________ bonding makes ice less dense than liquid water.
Hydrogen.
In the metabolism of cell, why is hydrolysis used?
Hydrolysis breaks down polymers.
During the breakdown of polymers, which of the following reactions takes place?
Hydrolysis.
-OH
Hydroxyl.
Where is the largest amount of DNA found in a eukaryotic cell?
In the nucleus.
Which of the following statements is FALSE?
Ionic bonds are generally stronger than covalent bonds.
What forms ionic bonds?
Ions with opposite charges.
A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?
It should be dissolve in water.
What are enantiomers?
Molecules that share the same chemical formula but are mirror images of each other.
Hydrophobic substances like vegetable oil are...?
Non-ionic or nonpolar substances that repel water.
____________ form between two atoms of the same element or between different elements that share electrons equally.
Non-polar covalent.
What are the building blocks of nucleic acids?
Nucleotides.
A covalent bond is one in which...?
Outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both.
This type of bond joins amino acids together.
Peptide bond.
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by...?
Polar covalent bonds.
What type of molecule is water?
Polar.
Dehydration synthesis leads to the formation of what?
Polymers.
Cellulose and starch are examples of _________________?
Polysaccharides.
Which of the following is not a functional group that can bond with carbon?
Sodium.
Water's high specific heat is mainly a consequence of the...?
Absorption and release of heat when hydrogen bonds break and form.
Where is the linkage made that combines two amino acids?
Between the carboxyl group of one amino acid and the amino group of the other.
What property of carbon makes it essential for organic life?
Carbon can form up to four covalent bonds, allowing it to form long chains.
Which two functional groups are always found in amino acids?
Carboxyl and aldehyde.
What is the name of the function group shown in Figure 4.4?
Carboxyl.
Plant cell walls contain which of the following in abundance?
Cellulose.
In ________________, water molecules are attracted to each other, keeping the molecules together.
Cohesion.
Water molecules are able to form hydrogen bonds with...?
Compounds that have polar covalent bonds.
What type of bond is formed when atoms share electrons?
Covalent
The shape of hair proteins is maintained by a combination of hydrogen bonds and covalent, disulfide bonds. Heat is sufficient to break the hydrogen bonds, but harsh chemicals are required to break the disulfide bonds. Why is it harder to break the disulfide bonds than the hydrogen bonds?
Covalent bonds are stronger than hydrogen bonds.
What type of bonds does carbon have a tendency to form?
Covalent.
Energy is released as a result of which of the following chemical reactions?
Dehydration synthesis.
What may a nucleotide of DNA contain?
Deoxyribose, thymine, and a phosphate group.
This type of bond can be found in lipids; it links a fatty acid to a glycerol backbone.
Ester linkage.
What is the reason why hydrocarbons are not soluble in water?
The C-H bond is non polar.
Define water's property of adhesion.
The attraction between water molecules and other molecules.
Which of the following is an example of a hydrogen bond?
The bond between the H of one water molecule and the O of another water molecule.
The partial negative charge in a molecule of water occurs because...?
The electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus.
Of what are phospholipids important components?
The plasma membrane of animal cells.
The alpha-helix and the beta-pleated sheet are part of which protein structure?
The secondary structure.
Which fat has the least number of hydrogen atoms?
Unsaturated fat.
The reactive properties or chemical behavior of an atom depend on the number of...?
Valence shells in the atom
Which of the following are molecules?
Water & cholorophyll.