BIOL1907 Module 1

Reproduction

property of life, new organisms are produced from one or more parent organisms.

Growth and development

property of life, cells growing in number and the quality/functionality of cells and systems improves.

Regulation and homeostasis

property of life, set of internal conditions maintained by living things despite changing environment.

Adaptation

property of life, a physical or behavioural feature that helps an organism survive better in their environment.

Evolution

property of life, the change in the inherited characteristics of biological populations over successive generations.

Hydrogen, Carbon, Nitrogen, Oxygen

What are the 4 most abundant elements in living organisms?

96.3%

What percentage do the 4 most abundant elements in living organisms make up of the human body mass?

Versatility

Carbon can bond with itself AND other elements in many different ways. What is this quality?

Diversity

Carbon forms molecules with similar shapes/formulas but vastly differing properties and functions. What is this quality?

Stability

Carbon has a sweet spot of what quality which makes it ideal for forming covalent bonds?

Hydrophobic

non-polar molecule, do NOT mix well with water (all C/H)

Hydrophilic

polar molecules, DO mix well with water.

Amphipathic

molecules which partially do mix with water and partially do not.

Versatility as a solvent

Emergent property of water: due to polarity, ideal for dissolving many substances, e.g. salt.

Moderation of temperature

Emergent property of water: ability to resist temperature changes.

Cohesive behaviour

Emergent property of water: tendency to stick together due to their ability to form H-bonds.

Expansion upon freezing

Emergent property of water: (uncommonly) water is less dense as a solid than as a liquid.

Emergent properties

characteristics or behaviours that arise when individual components of a system interact, but are not properties of the individual components themselves.

Evaporative cooling

reduction in temperature resulting from the evaporation of a liquid, which removes latent heat from the surface from which evaporation takes place.

Water, carbohydrates, lipids, nucleic acids, amino acids

What are the 5 building blocks of life? (macromolecules)

Monosaccharides

the simplest form of carbohydrate, e.g. glucose, fructose.

Disaccharides

double-sugars formed of 2 monosaccharides joined by a glycosidic bond.

Hydrolysis

process by which disaccharides are broken down with enzymes into monosaccharides for processing in the body (opposite of dehydration).

Glycosidic bond

a type of covalent bond that joins a carbohydrate molecule to another group, which can be another carbohydrate or another molecule.

Polysaccharides

carbohydrate macromolecules composed of many sugars.

Starch

carbohydrates used for storage in plants, made up of Amylose (unbranched) and Amylopectin (branched).

Glycogen

carbohydrates used for storage in animals, similar to starch but more extensively branched.

Cellulose

carbohydrates used for structure in plants.

Chitin

carbohydrates forming the exoskeleton of arthropods.

Peptidoglycan

are complex polysaccharides found in bacterial cell walls, acting as important targets for antibiotics.

Energy storage, structure

What are the 2 main functions of polysaccharides in organisms?

Dehydration synthesis

a chemical reaction where two molecules are joined together, and a water molecule is removed as a byproduct.

Energy stores, signalling molecules, protection and waterproofing, membrane structure

What are the 4 main functions of lipids in organisms?

Phospholipid bilayer

two-layer structure of phospholipid molecules that forms the basic structure of all cell membranes.

Saturated lipids

lipids with straight chains which are therefore rigid, tightly packed in the membrane.

Unsaturated lipids

lipids with kinked chains due to a double- or triple-bond which are therefore fluid, loosely packed in the membrane.

Amino group, carboxyl group, R group

What are the 3 main structures off the α-carbon in an amino acid?

Nucleoside

a compound consisting of a nucleobase and sugar.

Residue

the part of the monomer of the synthesised biopolymer that is incorporated into the growing chain.

Phosphodiester bond

Name the bond that joins nucleotides.

Negative charge, hydrophilic

What are the 2 properties of DNA that are attributed to the sugar-phosphate backbone?

Pyrimidines

Classification of the nucleobases cytosine, thymine, and uracil…

Purines

Classification of the nucleobases adenine and guanine…

N-glycosidic bond

What bond joins the sugar and nucleobase in a nucleotide?

Flexibility

What quality of DNA is attributed to the sugar-base bond?

Peptide bond resonance

partial double bond makes the peptide bond flat and rigid.

Side chain

aka the r group, differentiates each amino acid in the chain.

Complementary base pairing

in DNA, guanine always binds to cytosine and adenine always binds to thymine.

B-DNA double helix

most common form of the double helix where asymmetric strands run in opposite directions.

N to C terminus

In what direction are proteins synthesised and therefore the direction the sequence is conventionally written?

5' to 3'

In what direction are nucleotides synthesised and therefore the direction the sequence is conventionally written?

Messenger RNA (mRNA)

acts as intermediary of gene expression, uses gene information to specify the amino acid sequence of a protein.

Transfer RNA (tRNA)

adaptor molecules in protein synthesis — will carry amino acids to the ribosome complex to make proteins.

Ribosomal RNA (rRNA)

components of ribosomes used in translation.

Cytosine

Which of the 4 nucleobases is NOT generally stable and will deaminate to form uracil?

Deamination

the removal of an amino group from an amino acid or other compound.

Electrophoresis

Nucleic acids migrate in an electric field because they are charged allowing for what experiment?

Ethanol precipitation

Nucleic acids become insoluble when mixed with salt (+ive charge, so to neutralises charge) and ethanol allowing for what experiment?

The central dogma of molecular biology

a theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein.

The Proteome

all proteins expressed in any given cell.

The Transcriptome

all RNA in any given cell.

The Genome

refers to DNA, covers an organisms complete genetic information.

Chromosomes

repositories of genetic information.

Genes

organised segments of DNA/genetic information.

Large, linear

List 2 key features of eukaryotic genomes.

Small, circular

List 2 key features of prokaryotic genomes.

Histone proteins

protein that help condense DNA into chromatin.

Chromatin

complex of DNA and protein found in eukaryotic cells.

Universal genetic code

rules by which information from DNA and RNA is translated into proteins.

Universality, composed of codons, non-overlapping

List the 3 features of the universal genetic code.

Non-overlapping

each nucleotide is part of only one codon.

Codon

the combination of 3 bases which codes for an amino acid.

Reading frames

non-overlapping triplets set by the start codon that determine how the DNA sequence is interpreted.

Methionine

amino acid coded for by the start codon, AUG.

Stop codon

do NOT encode an amino acid as they signal the end of protein synthesis.

Redundancy/degeneracy in the genetic code

multiple codons CAN code for the same amino acid.

Open reading frame

the region from the start to the stop codon of the gene that encodes the protein/peptide.

Point mutation

one base pair changes.

Point mutation

e.g. CUU → CAU.

Silent

one base changes but amino acid stays the same.

Silent

e.g. CUU (Leu) → CUC (Leu).

Missense

one base change alters amino acid.

Missense

e.g. CUU (Leu) → AUU (Iso).

Nonsense

one base change creates a premature stop codon.

Nonsense

e.g. UAU (Tyr) → UAA (STOP).

Frameshift

addition or removal of bases changes the reading frame.

Insertion

one or more base pairs are added.

Insertion

e.g. CUU → CUAU.

Deletion

one or more base pairs are removed.

Deletion

e.g. CUU → CU—.

Duplication

segment of DNA copied twice.

Duplication

e.g CUU → CUUCUU.

Single nucleotide polymorphism (SNP)

a variation at a single position in a DNA sequence, i.e. a point mutation.

Semi-conservative

the 2 copies of DNA produced each have 1 strand from the original DNA and the other is a new strand.

Bi-directional

both strands must be replicated at the same time in opposite directions — complimentary strands are anti-parallel.

Origin of replication

a particular sequence in a genome at which DNA synthesis is initiated.

Nucleotide triphosphates (dNTPs)

the molecular precursors to DNA and RNA, consisting of a nucleotide with 3 phosphates.

Pyrophosphates

the phosphate groups released from the dNTP when it is added to the growing chain which breaks down to release energy.

RNA primer

a short segment of single-stranded RNA used as a binding site for DNA polymerase to initiate DNA synthesis.

Semi-discontinuous

DNA replication is continuous on 1 strand and discontinuous on the other.