Biology Ch 5 HW-B

Part B Identify the level(s) of protein structure present in this molecule. Select all that apply.

All levels apply primary secondary tertiary quaternary

DNA, or deoxyribonucleic acid, contains the genetic information that is used by all living things to produce their biomolecules essential for life. DNA is a double helix, with two strands. The two strands are held together by hydrogen bonds between complementary nitrogenous bases. The two strands are always complementary, ensuring that the DNA can be replicated accurately. The two complementary DNA strands always run in opposite directions: One runs from 5' to 3', and the other runs from 3' to 5', if you are looking along the strand, as seen in the image.(Figure 1) Part A Part complete Pair up the nucleotide bases with their complementary partners. Drag each item to the appropriate bin.

1. Adenine-Thymine 2. Guanine-Cytosine

Protein structure is conceptually divided into four levels, from most basic to higher order: Primary structure describes the order of amino acids in the peptide chain. Secondary structure describes the basic three-dimensional structures, αα-helices and ββ-sheets. Tertiary structure describes how the secondary structures come together to form an individual globular protein. Quaternary structure results from individual proteins coming together to form multi-subunit protein complexes. Part B Part complete Sort the images according to the level of structure in the proteins shown. Sort the items into the appropriate bin.

1. Primary Structure 2.Secondary Structure 3.Tertiary Structure 4. Quaternary Structure

Protein structure is conceptually divided into four levels, from most basic to higher order: Primary structure describes the order of amino acids in the peptide chain. Secondary structure describes the basic three-dimensional structures, αα-helices and ββ-sheets. Tertiary structure describes how the secondary structures come together to form an individual globular protein. Quaternary structure results from individual proteins coming together to form multi-subunit protein complexes. Part A Complete the following vocabulary exercise relating to the level of structure in proteins. Match the words in the left-hand column with the appropriate blank in the sentences in the right-hand column.

1.Primary structure is the sequence of amino acids in a protein. 2. Tertiary structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids. 3. Secondary structure describes the alpha-helices and beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain. 4. Quaternary structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex.

Scan along the standard sequences (O. kisutch, O. keta, and S. salar), base by base, identifying any bases that do not match the sequence from your fish sample. How many nucleotide bases differ between your sample (labeled as O. kisutch) and the standard sequence for O. kisutch? Sample labeled as O. kisutch 5'-CGGCACCGCCCTAAGTCTCT-3'O. kisutch (coho salmon) standard 5'-AGGCACCGCCCTAAGTCTAC-3'

3

Now do the same analysis for the other two standards. Sample labeled as O. kisutch CGGCACCGCCCTAAGTCTCTSample labeled as O. kisutchCGGCACCGCCCTAAGTCTCTO. keta (chum salmon) standard AGGCACCGCCCTGAGCCTACSalmo salar (Atlantic salmon) standardCGGCACCGCCCTAAGTCTCT Drag the values to fill in the table. Values may be used more than once. Not all values will be used.

3 85% 5 75% 0 100%

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand? 3'-UAAACG-5'3'-TUUUCG-5'3'-GCAAAT-5'3'-TAAACG-5'3'-ATTTGC-5'

3'-TAAACG-5'

Part B Part complete Write the complementary sequence for the following DNA sequence, in order from 3' to 5': 5′−CGATATTGAGCTAAGCTT−3′5′−CGATATTGAGCTAAGCTT−3′ Use all capital letters to write the DNA sequence.

3′−3′− GCTATAACTCGATTCGAA −5′

If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?

75

What percentage of the bases in the standard sequence for O. kisutch are identical to your sample? This value is called the "percent identity."

85%

Which molecule is a nucleotide?

ATP

Part A There are four levels of protein structure. These figures show primary, secondary, tertiary, and quaternary protein structure. Which level(s) of protein structure may be stabilized by covalent bonds?

Primary, tertiary and quaternary levels of protein structure

Part A These figures show the four levels of protein structure: primary, secondary, tertiary, and quaternary structure. Which level of protein structure is characteristic of some, but not all, proteins?

Quaternary level of protein structure

Part A Which feature of large biological molecules explains their great diversity?

The many ways that monomers of each class of biological molecule can be combined into polymers

Part C Part complete Rank the following base pairs according to their stability. Rank from most to least stable. To rank items as equivalent, overlap them. View Available Hint(s)

The more H...= The more stable Most stable= 3x H... Middle= 2xH... Least Stable= 1xH...

Part C What could happen if a mutation in a gene caused a hydrophobic amino acid in a polypeptide to be replaced by a hydrophilic amino acid?

The new amino acid would not form the same interactions with hydrophobic R groups, and the protein's shape would likely be affected.

Part A Your body contains tens of thousands of different proteins, each with a specific structure and function. The unique three-dimensional shape of each of these diverse proteins is based on several superimposed levels of structure. Which of the following statements is an accurate description of proteins?

The primary structure of a protein is the order of amino acids in a polypeptide, as coded for in the DNA of a gene.

Part D This table summarizes the results of your analysis. Based on these data alone, identify the best hypothesis for the species identity of your sample.

The sample is most likely S. salar (Atlantic salmon) because the 20-base nucleotide sequence is an exact match to the S. salar standar

Part C The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.

hydrogen bonds

A nucleotide is composed of a(n) _____.

phosphate group, a nitrogen-containing base, and a five-carbon sugar