DNA STRUCTURE AND FUNCTION

Define Triplet, Codon and Anticodon

** Triplet-A unit of three successive nucleotides in a DNA or RNA molecule that codes for a specific amino acid; a codon or anticodon. **Codon-a triplet of adjacent nucleotides in the messenger RNA chain that codes for a specific amino acid in the synthesis of a protein molecule. **Anticodon-a sequence of three nucleotides in a region of transfer RNA that recognizes a complementary coding triplet of nucleotides in messenger RNA during translation by the ribosomes in protein biosynthesis.

What is the process of DNA copying itself called?

DNA Replication

What are the differences in DNA and RNA?

The main difference between DNA and RNA is the sugar present in the molecules. While the sugar present in an RNA molecule is ribose, the sugar present in a molecule of DNA is deoxyribose. Deoxyribose is the same as ribose, except that the former has one more OH. DNA does not usually exist as a single molecule, but instead as a tightly-associated pair of molecules. These two long strands entwine like vines, in the shape of a double helix. This arrangement of DNA strands is called antiparallel. The asymmetric ends of DNA strands are referred to as the 5′ (five prime) and 3′ (three prime) ends. One of the major differences between DNA and RNA is the sugar, with 2-deoxyribose being replaced by the alternative pentose sugar ribose in RNA. The four bases found in DNA are adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T). A fifth pyrimidine base, called uracil (U), usually takes the place of thymine in RNA and differs from thymine by lacking a methyl group on its ring.

What are proteins made of? Describe their 4 levels of structure. Why is their structure so important?

*Proteins are made up of smaller building blocks called amino acids, joined together in chains. **Primary Structure-Refers to amino acid linear sequence of the polypeptide chain. The primary structure is held together by covalent bonds such as peptide bonds, which are made during the process of protein biosynthesis or translation. **Secondary Structure-Refers to highly regular local sub-structures **Tertiary Structure-Refers to three-dimensional structure of a single,double,or triple bonded protein molecule **Quaternary Structure-Refers to the three-dimensional structure of a multi-subunit protein and how the subunits fit together. In this context, the quaternary structure is stabilized by the same non-covalent interactions

What are the base pairings rules? Know and spell correctly the names of the bases, not just the letters.

-(A) adenine with (T) thymine -(G)guanine with (C)cytosine

Where does Protein Synthesis take place? What is another name for Protein Synthesis?

-Ribosomes -Translation

What are the 3 kinds of RNA and what are their functions?

-mRNA (messenger RNA) - carries genetic information from the nucleus to the cytoplasm -tRNA (transfer RNA) - brings amino acids to ribosomes during protein synthesis -rRNA (ribosomal RNA) - guides the translation of mRNA into a protein

Draw a Nucleotide and name the parts. Be able to spell them!

...

What is the anti-codon that would be complementary to the mRNA codon UAG?

AUC

What is the twisted ladder appearance of DNA called?

Double Helix

What is a codon that would be complementary to the DNA sequence CAT?

GUA

What does it mean for a protein to be denatured? Will the protein still work? Why or why not?

It means that the protein is basically dead and will not work any more. The protein will not work anymore because it is practically dead

What were 3 characteristics of enzymes discovered in Lab #8 (The Liver Lab). What evidence did you gather to support this?

They died in hot water, as cells died the enzymes remain intact and active only if the tissue was refrigerated, and that an enzyme is a catalyst. We found this out through our data tables and the lab prompt that was given to us.

What does it mean to say that the DNA molecule is "antiparallel"?

This means that structurally, the two strands of DNA (the two sides of the ladder) run in opposite directions. This property of antiparallelity allows for formation of the hydrogen bonds between the nitrogenous bases. These bonds are critical to the integrity of the molecule.

What is the process that makes RNA from DNA?

Transcription

Determine the amino acid sequence specified by the following strand of DNA: |TAC|AAA|GCG|TGA|GCA|CCG|TGT|CGA|

|MET|LYS|ARG|SER|ARG|GLY|SER|ALA|