AP Biology Lab 1.05-1.06

Description of Tertiary Protein Structure

3D group due to R-group interactions

A small protein is composed of 110 amino acids linked together in a chain. As shown in Figure 1, the first and last five amino acids in the chain are hydrophobic (have nonpolar and uncharged R-groups), whereas the remaining 100 amino acids are hydrophilic (have charged or polar R-groups). The nature of the R-group determines if the amino acid is hydrophobic or hydrophilic. A mutation results in the production of a version of the small protein that is only 105 amino acids long, as shown in Figure 2. Five of the hydrophobic amino acids are missing from one end of the chain. Which of the following best depicts the tertiary structures of the two proteins in water? The diagrams in the options are not drawn to the same scale as those in Figure 1 and Figure 2.

A (look at picture shown)

Which of the following best describes the formation of the bond shown in Figure 1 ?

A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2O

The salt in the solution helps ______________ to bind and clump together

DNA

DNA stands for _________________

Deoxyribose Nucleic Acid

Which of the following conclusions is most clearly supported by the representations of nucleic acid #1 and nucleic acid #2 ?

Nucleic acid #1 contains adenine-thymine base pairs, whereas nucleic acid #2 does not.

Description of Primary Protein Structure

Sequence of Amino Acids

A researcher analyzing an unknown genome discovered that the genome had the following nucleotide composition: 32% Cytosine 19% Guanine 28% Adenine 21% Uracil

Single-stranded RNA

DNA and RNA are nucleic acids that can store biological information based on the sequence of their nucleotide monomers. Figure 1 shows a short segment of each of the two types of nucleic acids. Which of the following best describes a structural difference between DNA and RNA?

The backbone of DNA contains deoxyribose, whereas the backbone of RNA contains ribose.

Researchers compared similar proteins from related organisms in different habitats. They found that the proteins from organisms living in harsh environments had a greater number of cysteine amino acids than did proteins from organisms not living in harsh environments. The structure of cysteine is shown. Bonds can form between the sulfur atom of different cysteine amino acids (S-S-S bonds). Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins?

The change leads to increased protein stability because of an increased number of S-S bonds in the tertiary structure of the proteins

DNA precipitates out of the strawberry layer into the __________________ layer and then can be easily removed.

alcohol

The CFTR protein is made up of 1,480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain. Which of the following levels of protein structure will be affected by this deletion?

all will be affected: primary, secondary, tertiary, and quaternary

Description of Quaternary Protein Structure

bonding of multiple polypeptide subunits

Description of Secondary Protein Structure

hydrogen bonds forming alpha helices and pleated sheets

Alcohol is ____________ dense than the strawberry solution, which means that it will form a layer on top.

less

The detergent molecules break apart and separate the cell ___________________

membrane

Strawberry cells are _________________, while human cells are diploid.

octoploid