Chapter 1 Flashcards
What is biochemistry?
The study of life at the molecular level
The application of principles of chemistry to explain biology
The study of the molecular logic of life
What do all organisms use in common?
A common repertoire of building blocks to create common nucleic acids, proteins, polysaccharides, and lipids
A common core of essential biomedical processes
What are the 6 distinguishing features of living organisms?
- High degree of chemical complexity and organization
- Systems for extracting and using energy from environment
- Defined functions for each the organisms components and interactions
- Mechanism for sensing and responding to alterations in their surrounding
- A capacity for self replication and assembly
- A capacity to change over time by evolution
What is he chemical foundation of life?
Carbon oxygen and hydrogen account for 98% of most organisms
Humans big four are hydrogen then oxygen then carbon then nitrogen
Water accounts for much of the oxygen and hydrogen
Was is silicon the second best candidate to carbon for the chemical foundation of life?
It can also form four covalent bonds
It is highly abundant in the earths crust
Why are humans based in carbon rather than silicon?
Carbon-to-carbon bonds are stronger
More energy is released by combustion of carbon carbon bonds
Combustion products of carbon (CO2) are soluble and remain active in biosphere
What determines the structure, function, and properties of a biomolecule?
The collective properties of the functional groups within that biomolecule
Structure dictates function
Once we understand the structure function relationship, what can we do?
Can predict function, for diseases can develop molecular treatments
What is conformation?
Flexible spatial arrangement of atoms within a molecule
Can be changed without breaking bonds
What is configuration?
Fixed spatial arrangement of atoms within a molecule
Cannot he changed without breaking bonds
Ex: double bonds or chiral centres
What are geometric isomers?
They have the same chemical formula but differ in the arrangement of groups
“Cis-trans”
Cis: groups on the same side as the double bond
Trans: groups on opposite sides of the double bonds
What is a chiral carbon?
How can you find the amount of stereoisomers in a molecule with chiral carbons?
A carbon atoms that has four DIFFERENT chemical groups attached
A molecule with n chiral carbons will have 2^n stereoisomers
What are stereoisomers?
What are the sub levels enantiomers and diastereomers?
Stereoisomers- non superimposable molecules that differ in configurations at a chiral centre (hands are stereoisomers of eachother)
Enantiomers- mirror images (rotate a plane of polarized light in opposite directions (hands are enantiomers)
Diastereomers- not mirror images
What are the three advantages of polymers for biomolecules?
- Simplicity of chemistry (one reaction for polymerization, one for degradation)
- Recycling (they can be digested back into building blocks)
- Incredible diversity of polymer length and sequence
What are the four classes of biomolecules?
Proteins- linear polymers of amino acids
Nucleic acids- linear polymers of nucleotides (genetic information)
Polysaccharides- linear or branched polymers or sugars (cellular recognition roles)
Lipids- fats and aggregates of fats that store energy
What three fundamental features do all cells share?
Plasma membrane
Cytoplasm
Nucleic acid
What are the two basic classes of living organisms?
Prokaryotes- small single cell rapid growth and division
Eukaryotes- large multicell contains organelles
What do humans have more of, Eukaryotes or prokaryotes?
30 trillion eukaryotic cells
But it’s home to 10-100 trillion prokaryotic cells
Prokaryotes are critical for our health (help us digest food, our second brain)
What are the two experimental approaches to studying molecules in isolation?
In vitro (in glass) studies behaviour of molecules outside the context of the cell and organism In Vivi (in the living) studies occur within the context and complexity of the cell or organism
Experiments that succeed in vitro often fail in Vivo
What is the first law of thermodynamics?
In any physical or chemical change, the total amount of energy in the universe remains constant, although the form of the energy may change
Cells are highly affective transducers of energy
What is the second law of thermodynamics?
The tendency in nature is toward ever greater disorder: the total entropy (disorder) of the universe is continually increasing
What is the definition of free energy? (Equation)
G= H - TS ΔG= ΔH - TΔS
G- Gibbs free energy
H- enthalpy- number and kinds of bonds
T- temperature in kelvins
S- entropy- the degree of randomness
How do you know if an equation is endergonic or exergonic?
Endergonic- ΔG>0
Non spontaneous process that needs input of energy
Exergonic - ΔG<0
Spontaneous process releases free energy
What does energy coupling do?
Couples energy requiring endergonic reactions to reactions that liberate free energy (exergonic) which causes cells to drive thermodynamically unfavourable reactions
What links anabolic and catabolic reactions?
ATP
What dictates the sequence of amino acids incorporated into the corresponding protein?
The nucleotide sequence within Genes
The amino acid sequence then in turn dictates the structure of the protein
The structure of the protein then in turn dictates the biological activity of the protein
