Biomolecules 1 Flashcards
DNA and RNA Composition
Nucleotide chains
Components of a nucleotide
Phosphate (negatively charged), 5 Carbon Sugar, Nitrogen Base
Genetics Central Dogma
DNA transcripted to mRNA translated to Protein
2 Nitrogen Base Types
Pyrimidine (1 ring) + Purine (2 Rings)
Pyrimidine def. + examples
1 Ring. Thymine/Uracil and Cytosine
Purine def. + examples
2 Rings. Adenine + Guanine
Complimentary Pairs
Guanine + cytosine (3 H bonds). Adenine and Thymine (2 H bonds)
DNA Bases + Sugar
A,T,C,G and Deoxyribose
RNA Bases + Structure
A,U,C,G + Ribose
Transcription Steps (DNA to mRNA)
Initiation, Elongation, Termination
Transcription Initiation Desc.
RNA polymerase binds DNA + unwinds 17-18 base pair segment
Transcription Elongation Desc.
RNA polymerase synthesises mRNA along DNA template until terminator region is reached
Transcription Termination Desc.
Terminator sequence causes RNA polymerase to pause and dissociate. RNA peels away + DNA rewinds to double helix
DNA Structure
Double Helix, 2 Strands
RNA Structure
Single Strand
Translation Steps Desc.
mRNA binds to ribosome in cell cytoplasm. tRNA carries anticodon bases complimentary to mRNA’s codons.
Polypeptide Formation Phases
Building Unit of A Protein
Amino Acid
Open Complex Def.
Exposed 17-18 base pair segment
3 Components of a Protein
‘R’/’side’ Chain
2 Types of Amino Acids (by R groups)
Non-Polar (Hydrophobic) and Polar (Hydrophilic)
Non-Polar Amino Acid Types
Aliphatic (chain) and Aromatic (Ring)
Polar Amino Acid Types
Neutral, Alkaline (positive) and Acidic (negative)
More amino acid varied Characterstics
Small (can pass through kidney), Branched, Sulpher in side chains, located at protein bend, phosphorylated, glycosylated, nitrosylated
Phosphorylated Def.
Adding phosphate molecule
Glycosylated Def.
Adding sugar molecule
Nitrosylated Def.
Adding of nitroxide
Primary Structure Desc.
Polypeptide chain. Peptide bonds between carboxyl group (end) of 1 and amino group (start) of other
Secondary Structure Desc.
Rearrangement of primary determined by hydrogen bonds. Folding controlled by amino acid sequence
2 Examples of Secondary Structure
Alpha Helix and Beta Pleated Sheet
Tertiary Structure Desc.
Folding of secondary into globular form. Hydrophobic amino acids on inside and hydrophilic on outside. Stabalised by bonding and interactions between side chains
3 Types of Bonds in Tertiary Structure
Disulphide (2 cytosines), Ionic, Hydrogen
Interaction in Tertiary Structures
Hydrophobic
Quaternary Structure Desc.
Arrangement of more then 1 polypeptide (2+ polypeptide chains, that are the same/different). Held together by non-covalent interactions + interchain disulphide bonds
Covalent Bonds in a protein
Peptide + Disulphide
Non-Covalent Bonds in a Protein
Hydrogen, Ionic, Hydrophobic Interactions
Native Confirmation of Proteins Def.
Functional fully folded protein structure that determines biological function of the protein
Potential Biological Functions of Protein
Enzymatic, Protection, Regulation, Signal Transduction, Storage + Transport
Post Translational Modifications
Chemical modification of protein after translation by attaching a functional group. Changing protein function
