Intro to Bio-molecules Flashcards
define atoms
‘incapable of being divided’
define (Bio/macro) Molecules
two or more atoms
define cells
smallest living units
define tissue
similar cells with common function
define organs
two or more tissue types
define organ system
cooperative group of organs
define ionic bonding
The electrostatic attraction between oppositely charged ions e.g. NaCl
define covalent bonds
sharing of electrons e.g. CH4
what does equal sharing of electrons give in covalent bonds
non polar bond e.g. CH4
what does unequal sharing of electrons give in covalent bonds
polar bond e.g. water
describe hydrogen bonds
-hydrogen that is covalently attached to an electronegative atom forms attraction with another v electronegative atom
-they are directional bonds so donor hydrogen and acceptor have to be in same plane e.g. DNA nucleotides
-H bonds are important for DNA and 2° protein structure
describe electrostatic forces
-oppositely charged groups attract each other
-amino acids can be ionised and can have interactions between them
-weakened by water and salts becasue they are charged so will compete for electrostatic attraction
-charge on amino acids change according to pH
-this force forms between enzymes and substrate
Describe Van der Waals forces
-non specific attraction
-transient asymmetry of electron distribution induces the same in other atoms and an attraction occurs bw the two
-Weak but significant when a number can form at close distance
describe the bonds in water
-Biologically important- solvent for large array of molecules
-Electrically polar bc +ve H and -ve O
-Hydrogen bonds- highly cohesive
-Weakens electrostatic & hydrogen bonds
-Nonpolar groups/molecules cluster in water – hydrophobic attractions
-Water-free microenvironments needed for polar reactions bc water will interfere w electrostatic and hydrogen bonds
give polymer for fatty acid
Diglyceride, Triglyceride
give polymer for monosaccharide
Polysaccharide
give polymer for amino acid
protein
give polymer for nucleotide
nucleic acid (dna, rna)
describe lipids
-structurally diverse
-insoluble in water
-do not form large polymers bc no end to end bonding
what are the functions of lipids?
Cell membranes (phospholipids)
Storing energy
Insulation, protection & absorbing shocks
Controlling cell activity (steroid hormones)
what are fatty acids?
long chain carbon molecules which can be saturated or unsaturated
what is a triglyceride?
a neutral fat made up of glycerol (sugar alcohol) and three fatty acids
what is a phospholipid?
lipids made of glycerol, phosphate and two fatty acids (one FA replaced with phosphate)
what is a sterol?
Cholesterol, steroid hormones
what is the structure of sterol
overlapping C-H rings
why is sterol considered to be lipids?
because they are hydrophobic
describe Low density lipoprotein (LDL)
Lipoprotein that carries fatty acids & cholesterol around the body
High levels associated with the development of atherosclerosis (thickening or hardening of the arteries)
what are carbohydrates?
sugars and polymers of sugars
what are the functions of carbohydrates?
-short term energy source
-make structural materials e.g. cellulose
-act as molecular tags - glycosylation
-contribute to structure of nucleotides
structure of carbohydrates and examples
Monosaccharides- five or six sided ring e.g. glucose
Disaccharide e.g. sucrose
Polysaccharide e.g. starch
what are proteins?
Amino acids linked by peptide bonds
Most abundant & diverse bio-molecule in cells
what are the functions of proteins?
-structure, muscles made of actin and myosin, hair
-cell transport
-contraction
-signalling
-enzymes
-cell attachment
Protein structure
Polypeptides of Amino acids (20)
Peptide bonds
Complicated structures (Primary, secondary, tertiary, quaternary)
describe collagen
Most abundant protein in the body
Support for tissues, skin etc.
Dentin & bone are mineralised collagen
how does collagen structure relate to function
Triple, cross-linked helix
describe nucleotides
a nitrogenous base, a phosphate group, and a pentose sugar
C, N & O ring with 5 carbon sugar and phosphate
what is the function of nucleotides?
to store information needed to control and build cells
name the two main types of nucleic acids
Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)
messenger, transfer, ribosomal, viral
describe DNA
Double helix,
A, G (Purine), T, C (pyrimidines)
Storage of information in the nucleus
describe RNA
single stranded,
A, G, U, C nucleotides
Made in the nucleus & mRNA transported
describe Amelogenesis imperfecta (AI)
Amelogenesis = enamel formation
Teeth discoloured and susceptible to cavities & wear
Mutations in several genes including those coding for ameloblastin & enamelin
describe ATP
Adenosine triphosphate (ATP)
-made up of ribose sugar, adenine base and phosphate chain
-stores energy for catabolic and anabolic reactions
describe nadh
Nicotinamide adenine dinucleotide (NADH)
Principle e- donor in respiratory chain
Recycled
why is RNA easy to degrade?
because it is single stranded
what are the functions of biomolecules?
-molecular switch
-proteins take part in pathways that create a signal
-molecular motors e.g. flagella/cilia
-sources of energy e.g. ATP
-transport e.g. Hb
-information store eg. DNA
-antibodies/enzymes
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