Biology Flashcards: RNA and DNA Functions

RNA and DNA Functions

• DNA and RNA are essential for protein synthesis within cells.
• DNA provides the genetic instructions; RNA acts as the worker carrying those instructions.

Genetic Inheritance

• RNA and DNA contribute to the formation of genes, which are hereditary units.
• Individual DNA is inherited from both parents, creating a unique combination from each.

Universal Presence of DNA

• All living organisms possess DNA as a fundamental component of life.

Building Blocks of Nucleic Acids

• Nucleic acids, DNA and RNA, are constructed from monomers called nucleotides.

Nitrogen Bases in DNA

• DNA contains four nitrogen bases: adenine, cytosine, guanine, and thymine.
• In RNA, uracil replaces thymine found in DNA.

Nucleotide Bonding in RNA

• Nucleotides bond through a dehydration reaction, resulting in covalent bonds between pentose sugars and phosphates.

DNA Structure

• DNA is assembled with its nucleotides forming hydrogen bonds between specific bases: adenine pairs with thymine, and guanine pairs with cytosine.

Evolution of DNA

• Scientists hypothesize DNA evolved from RNA, with RNA initially encoding information before the formation of double-stranded DNA.
• The backbone of DNA is composed of alternating sugar and phosphate groups.

Differences between RNA and DNA

• RNA has uracil, is single-stranded, and is found throughout the cell.
• DNA has thymine, is a double helix structure, and is localized in the nucleus.

ATP Structure and Function

• ATP, or adenosine triphosphate, consists of three phosphate groups, ribose, and adenine.
• Serves as the primary energy currency of cells.

Protein Synthesis

• Proteins are constructed from amino acids, which are their basic building blocks.
• Dietary sources provide amino acids, which are broken down to form new proteins.

Amino Acid Structure

• Amino acids share three common components:
  • Alpha carbon with a hydrogen,
  • Amino group with nitrogen,
  • Carboxyl group with carbon and oxygen/hydrogen.

Amino Acid Count

• There are a total of 20 different amino acids.

Variation in Amino Acids

• The distinctive feature of each amino acid is the R group, which provides different chemical properties.

Polypeptide Formation

• Amino acids bond through dehydration synthesis with the assistance of ribosomes during protein synthesis.
• The resulting structure from this process is a polypeptide, held together by peptide bonds.

Distinction Between Polypeptide and Protein

• A polypeptide is a simple chain of amino acids.
• A protein consists of one or more polypeptides folded into a specific three-dimensional shape.

Polypeptide Folding

• Folding of polypeptides is dictated by the sequence of amino acids and the properties of their R groups.
• The specific shape is determinant for the protein's function.

Denaturation of Polypeptides

• Extreme temperatures or pH levels can lead to denaturation, rendering the polypeptide nonfunctional.