Unit 4, Concept 1

This is a macromolecule that carries our genetic information (DNA). Has the blueprint/instructions for making proteins.

DNA and RNA are these two types

Deoxyribonucleic acid is what this stands for.

Ribonucleic acid is what this stands for.

These make up nucleic acids. They are monomers of DNA.

These have sugar, phosphate, and nitrogen base for their 3 parts.

Deoxyribose and Ribose are examples of this

Adenine, Guanine, Cytosine, Thymine (DNA only), and Uracil (RNA only) are these.

This item’s shape is a double helix (a twisted ladder)

Strong covalent bonds and weak hydrogen bonds are these two bonds.

Thymine and Guanine bond with these in DNA.

This is called the “complementary base pairing rules“.

(small word, big base) These are big bases that have the nitrogen bases Adenine and Guanine.

(big word, small base) These are big bases with Cytosine and Thymine.

Purines are big bases with nitrogen bases Adenine and Guanine, while Pyrimidines are small bases with nitrogen bases Thymine and Cytosine.

These rules state that A=T and C=G.

These bonds hold the nitrogen pairs together

These two nitrogen bases share double bonds (2 bonds)

These two bases share triple bonds (3 bonds).

This term means the strands run in opposite (or antiparallel) directions.

DNA has two strands that run, and one starts with a phosphate and runs in the 5’ to 3’ direction. The other strand starts with deoxyribose (sugar) and runs in the 3’ to 5’ direction. Since these strands will always alternate and go in different directions, they are antiparallel.

This end is the phosphate end (“fa” sound - phosphate and five make the “fa” sound).

This end is the sugar (deoxyribose) end.

These bonds are found in the middle of the DNA molecule. These bond the nitrogen bases together.

These bonds are found on the outside of a DNA molecule. These bond the phosphates and sugars together (nucleotide).

A nucleotide has a phosphate bonded (covalently) with sugar (deoxyribose). That sugar is also being bonded to a nitrogen base, which is also bonding (hydrogen bond) with another nitrogen base.

Tip: When we were having to cut out little pieces of DNA and put them together with the phosphates, sugars, and bases (Adenine, Thymine, etc.), those were nucleotides. When we put them all together in class, those all together made a DNA molecule, or nucleic acid.

For its structure, it has:

• Double Helix - sugar and phosphate form “sugar phosphate backbone", nitrogen bases bond in the middle.

• Nitrogen bases paired complementary with hydrogen bonds.

• It is antiparallel and runs in opposite directions (one strand runs in 5’ to 3’, the other runs in 3’ to 5’).

Genes are pieces/sections of DNA, chromosomes are long strands of DNA bunched up and coiled, and a strand is a long molecule with nucleotides/nitrogen bases.

During DNA Replication, DNA is unzipped by Polymerase. Enzymes help find the complementary bases (basically match them up) according to the rules - A=T, C=G. Two identical DNA molecules are made, one “new” strand and one “old” strand.

• The leading strand needs 1 RNA primer but the lagging needs many.

• The leading strand is made continuously but the lagging strand is discontinuously.

• The lagging strand creates Okazaki fragments and the leading doesn’t.

• The enzyme Helicase unzips DNA into 2 strands.

• Enzyme DNA Polymerase adds complementary nucleotides to the template strands.

• Enzyme primase makes short RNA primers.

• DNA ligase seals DNA gaps, connects DNA pieces by making bonds.

This is the RNA that initiates DNA synthesis.

These fragments are short sequences of DNA nucleotides that are made and later linked by DNA ligase to make the lagging strand.

In this model, DNA’s 2 strands unwind and each help create a new, complementary strand.

This is where DNA’s old (original) strands unzip and help create new strands that complement them. There one new strand and one old one, which is the original.