Lec 2: Introduction to Biological Molecules Flashcards
“Explain some of the properties of carbon relevant to its role as the major constituent of biological molecules”
- carbon has 4/8 outer electrons
- carbon is tetravalent, this means that it can form 4 bonds other atoms/groups e.g. C,H,O,N,S
- It shares electrons with C-atoms and other electron deficient atoms to share electrron pairs
- carbon based molecules are often very large and held by strong covalent bonds
“Explain with the polar nature of water, hydrogen bonding and the biological importance of water”
Water’s Polarity:
- A water molecule is made up of 2 Hydrogen atoms and an Oxygen atom
- the oxygen atom in the molecule is highly electronegative so the electrons are pulled towards it and away from the hydrogen atoms
- therefore the hydrogen atoms a have a slightly positive charge
- the oxygen atom has a slightly negative charge
Hydrogen bonding:
when water molecules are close together their positive and negative regions are attracted to the oppositely charged regions of nearby molecule
the partially positive hydrogen atom forms a hydrogen bond with the lone pair on the highly electronegative atom e.g O,F,N,Cl,Br
Biological Importance:
because of water’s properties, water is important bc;
- poplar substances can dissolve in it (universal solvent) and it aids the movement of chemicals during diffusion
- It acts as a lubricant in joints and tissues aslo moistens the epithelial surface for effective gas exchange
- It regulates body temperature, qater requires heat to turn to vapour – Sweat absorbs heat from the skin when evaporating
“describe a variety of functional groups that are important in biology”
“explain the difference between biological polymers and monomers and describe how they are produced and broken down”
polymer: macromolecules composed of building blocks or monomers
monomer: where monomers join together with covalent bonds to form long chains or macromolecules
why is carbon the basis of living material?
-carbon can form 4 bonds with other atoms and a wide variety of chemical groups
How many protons, neutrons and electrons does a carbon atom have?
Protons: 6
Electrons: 6
Neutrons: 6
which atoms does carbon most commonly form covalent bonds with?
carbon C
hydrogen H
oxygen O
nitrogen N
sulphur S
what is meant when it is said that carbon is tetravalent?
can form 4 covalent bonds
NOTE about Carbon in Bio
Valence and low atomic weight give carbon unique properties that account for the diversity and stability of carbon-containing compounds and its role in biological molecules
Identify the functional group
alkene/ethene
Identify the functional group
alkyne/ethyne
Identify the functional group
thio/sulfydryl
Idenitfy the functional group
amine (amino)
Identify the functional group
thiol/sulfhydrdryl
Identify the functional group
Ketone
CO
Identify the functional group
aldehyde
CHO
Identify the functional group
Haloalkane
Identify the functional group
Ether
(oxygen atom bonded to two alkyl or aryl groups)
Identify the functional group
carboxylic acid
(alcohol and acyl halides, acid anhydrides, esters, and amides)
Identify the funcional group
ester
(carboxylic acid and alcohol)
Identify the funcional group
Amide/peptide
(secondary amines and carboxylic acids)
Identify the funcional group
phosphate
what is a macromolecule?
Large biological molecules with repeating subunits and many functional groups
what are the four biologically important macromolecules?
– Carbohydrates
– Lipids
– Proteins
– Nucleic acids
what are monomers?
macromolecules composed of building blocks or monomers
what are polymers
where monomers join together with covalent bonds to form long chains or macromolecules
give examples of monomers
- monosaccharides
- amino acids
- nucleotides