Topic 2 - Genes & Health Flashcards
What is The Basic Structure of an Amino Acid?
H H O
\ | //
N - C - C
/ | \
H R OH
What Bond Joins Together Amino Acids?
Peptide bond
What Does a Chain of Amino Acids Form?
A polypeptide chain (protein)
In What Reaction Are Peptide Bonds Formed?
Condensation reaction
What Happens In The Primary Structure of a Protein?
Amino acids join together by peptide bonds, in a condensation reaction to form polypeptide chains
What Happens In The Secondary Structure of a Protein?
The amino acid chain folds into either an alpha helix or a beta-pleated sheet
What Bonds Form Between The Folds In The Secondary Structure?
Hydrogen bonds
Where Do The Hydrogen Bonds In The Secondary Structure Form?
Between the carboxyl and amine groups
What Happens In The Tertiary Structure of a Protein?
A 3D-shape is formed by chemical and hydrophobic interactions between the R groups. (Hydrophobic on the inside and hydrophilic on the outside to attract polar molecules).
When Does The Quaternary Structure Take Place?
When a protein has more than one polypeptide chain
What Is a Conjugated Protein?
A protein with another chemical group, associated with its polypeptide chains
What Is a Globular Protein?
A protein with polypeptide chains folded into a spherical shape
What Is a Fibrous Protein?
A protein that remains in long chains, connected with cross-links
What Are The Properties of Globular Proteins?
- Soluble due to hydrophilic side chains
- Important in metabolic reactions
- (e.g. enzymes, antibodies, transport proteins)
What Are The Properties of Fibrous Proteins?
- Insoluble
- Cross-linked with extra polypeptide chains for strength
- (e.g. keratin, collagen and bone)
What Is Phase 1 of Protein Synthesis?
Transcription
What Is Phase 2 of Protein Synthesis?
Translation
What Are the Stages of Transcription?
- RNA polymerase unzips the DNA
- Template strand is transcribed into mRNA, containing the same base sequence
- Phosphodiester bonds Form between the nucleotides
- mRNA leaves the nucleus through pores and DNA zips back up
What Is a DNA Coding Strand Also Known As?
Sense strand
What Is the Template Strand Also Known As?
Anti-sense strand
What Are the Stages Of Translation?
- mRNA attaches to a ribosome
- mRNA codons pair with specific anti-codon for a specific protein
- Small ribosome sub-unit binds to mRNA’s start codon and then face tRNA binding site in large sub-unit
- As each tRNA pairs up, an amino acid chain forms and the previous tRNA leaves
- Continues until the stop codon
What Is Diffusion?
The movement of substances from a high concentration to a low concentration through a phospholipid bilayer
- Passive (no energy needed)
- Down a concentration gradient
- Transports hydrophobic and small uncharged molecules
What Is Facilitated Diffusion?
Transport from high concentration to low concentration through channel or carrier proteins
- Passive
- Down a concentration gradient
- Transports hydrophilic molecules/ions
What Is Osmosis?
Diffusion of free water molecules from a low concentration to a high concentration through a phospholipid bilayer
- Passive
What Is Active Transport?
Transport from a low concentration to high concentration through carrier proteins that change shape
- Requires energy from ATP
- Against a concentration gradient
What Is Exocytosis?
The bulk transport of substances out of a cell
- Vesicles fuse with CSM to release contents
What Is Endocytosis?
Bulk transport of substances into a cell
- CSM creates vesicles to bring substances into the cell
