Chemistry of Biology

Found in all DNA nucleotides

-deoxyribose sugar
-phosphate

Found only in specific DNA nucleotides

-guanine
-adenine
-thymine
-cytosine

Adenine forms base pairs with _____.

Thymine

Cytosine forms base pairs with _____.

Guanine

Guanine forms base pairs with _____.

Cytosine

Thymine forms base pairs with _____.

Adenine

How many DNA nucleotides (in total) are present in this segment of DNA?

Eight

When bonds between atoms are graphically depicted, a solid line represents covalent bonds, and a dotted line represents hydrogen bonds. Based on this figure, hydrogen bonds are located between which components of DNA nucleotides?

between two nitrogen-containing bases

The two strands in a DNA helix are described as being antiparallel, or in opposite orientations. If one DNA strand is in the 5' to 3' orientation, the complementary DNA strand is orientated in which direction?

3' to 5'

DNA

-the pentose sugar is deoxyribose
-the nitrogen-containing bases are adenine (A), cytosine (C), guanine (G), and thymine (T)
-it functions by determining the heredity of trait
-it is double-stranded in cells and most DNA viruses

RNA

-the nitrogen-containing bases are adenine (A), cytosine (C), guanine (G), and uracil (U)
-the pentose sugar is ribose
-it functions in protein synthesis
-it is single-stranded in cells and most RNA viruses

Choose from the following statements the one that best describes the reactions illustrated in the figure above.

Using energy, an enzyme removes a hydroxyl group from the carboxyl group of one amino acid and a hydrogen atom from the amino group of another amino acid to join the amino acids in a dehydration synthesis reaction that releases water. Alternatively, anoth

Choose the statement that does NOT pertain to amino acids.

Amino acids always contain a sulfur atom in their R-side group.

The formation of a peptide bond to link two amino acids together is a special type of __________.

dehydration synthesis reaction that removes a hydroxyl group from the carboxyl end of the amino acid and reforms the bond with the nitrogen from the amino group that has lost a hydrogen atom

Rank the following groups in the order that they contribute to the structure of a protein.

1. Amino acid sequence a-b-c-d-e
2. Alpha-helix or beta-sheet
3. Helix-sheet-turn-helix
4. Polypeptide A joined to polypeptide B, which joins to polypeptide C

Which of the following statements about the atom is 12/6 C FALSE?

It has 12 neutrons in its nucleus.

Gastric juices have a pH of 1 or 2. This would indicate which of the following?

numerous H+ ions and a low pH

In the figure, which is an alcohol?

c

Which are the primary molecules making up plasma membranes in cells?

lipids

What do genes consist of?

nucleic acids

Which of the following is the type of bond holding K+ and I- ions in KI?

ionic bond

Which type of bond is found between Na+ and Cl- ions in NaCl?

ionic bond

Which of the following describes inorganic molecules?

small and structurally simple compounds, which typically lack carbon and in which ionic bonds may play an important role

The density of liquid water is greater than the density of ice.

True

Identify the following reaction: Lactose + H2O ? Glucose + Galactose

hydrolysis reaction

Which type of molecule NEVER contains a phosphate group?

triglycerides

Structurally, ATP is most like which type of molecule?

nucleic acid

Isotopes are atoms of the same element that differ in their

neutron number

What do H2O, NaCl, CO2, and HCl all have in common?

all inorganic

What part of a phospholipid forms hydrophobic tails?

fatty acids

DNA

-the pentose sugar is deoxyribose
-the nitrogen-containing bases are adenine (A), cytosine (C), guanine (G), and thymine (T)
-it functions by determining the heredity of trait
-it is double-stranded in cells and most DNA viruses

RNA

-the nitrogen-containing bases are adenine (A), cytosine (C), guanine (G), and uracil (U)
-the pentose sugar is ribose
-it functions in protein synthesis
-it is single-stranded in cells and most RNA viruses

Choose from the following statements the one that best describes the reactions illustrated in the figure above.

...

DNA

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