Chemicals Of Life Flashcards
Srikandi 4flat together
Living organism made from
Organic and inorganic molecule
What is organic molecule
Large, complex molecule with backbone of C atom
What is inorganic molecule
Small, simple molecule that lack of C atom or have only 1
Atom combines by chemical bonding to form
Molecule
4 important bonds
Ionic bonds
Covalent bonds
H bonds
VDW bonds
Ionic bond involves
Transfer of electron
What happen in ionic bond
1 atom lose e form +ve ion
1 atom gain e form -ve ion
Charge different so they attract each other
Covalent bonds involve
Share 1 or more pairs of e
Types of covalent bond
Polar
Non polar
What is non polar c.b
Atoms same proton no. Exert
Same pull and electron, share e equally
Charge in non polar c.b
No diff in charge between two end of atom
What is polar c.b
Atoms of diff elements (diff proton no.) Dont exert same pull on e
Atom that pull more e become slightly -ve
Atom pull less e become slightly +ve
Charge in polar c.b
No net charge
Define electronegativity
Tendency of atom to attract electron towards itself. Depends on atomic no. and dist between valence e and nucleus (bak kata teacher noor, nak jadi negative ion)
Try explain polar c.b in water
O more electro-ve than H. Electron shared are pulled more towards O. O slightly -ve , H slightly +ve
What is H bond
Attraction between more electro-ve atoms (from one polar c.b)and H atom (from another polar c.b)
Can H bond be in same or diff molecule?
Both
What is VDW interactions
A molecule with non polar c.b may have +ve and -ve charged regions. This is bcs e is in constant motion, they are not symmetrically distributed
Its a weak interaction and occur only when atoms and molecules are very close
Importance of water
Surround the cell
70-95% in cell
Reactant of many chemical reaction in life
Structure of water
Have 1 O and 2 H
O > electro-ve than H
So O slightly -ve , H slightly +ve
Form polar molecule
Charge in water
No net charge but charge are unevenly distributed
Why water liquid can flow
The H bond between water molecule constantly form break reform
What makes water stable compound
Has H bond between molecules
Collective H bond produce strong structure allowing water to be stable compound
Due to polarity
Water molecule attracts and form bond (H bond) with each other
5 properties of water
Cohesion adhesion High specific heat cap. High heat Vap Lower density of ice Water as principal solvent
What is adhesion
Attraction between water and polar substance like container
Make things wet
Cohesion
Attraction betwern water molecules that produce surface tension (skin of water)
Allow insects to walk on water (water strider)
Water surface provide breeding and feeding place
Adhesion+cohesion
Capillary action
What is capillary action
Tendency of water to move in narrow tube against the gravity force
How capillary action works in plant
Capillary action in plants allow water to flow upward through the vascular system. As water evaporate from leaves surface, water molecules that are cohered to that evaporating molecules move upward. The water stays in tubular shape bcs it i adhered to the lining of plant vascular tube
Define specific heat cap
Amount of heat absorbed or lost by 1g substances to change it temp by 1°C
What is specific heat cap of water
4.2 J (large amount)
Why water has high specific heat cap
Bcs heat is needed to break the H bomds between water molecule therefore change in temp only cause slight change in water temp
Significance of high spec heat cap
Temp change is minimized. Water helps to moderate temp of organism and environment
Define heat of vaporization
Quantity of heat that a liquid absorb for 1g of it to be converted from liquid to gas
Why high heat vap
Heat energy used to break H bonds between water molecules so they can escape as gas
Significance of high heat vap
Heat is transferred fom surrounding to water molecules
Explain lower density of ice
Water reaches its high density at 4°C. As it cools below 4°C, density of water decrease. This is bcs the liquid water expand as it freeze. When reaching 0, water expel less energy and H bonding occur. Water molecule is locked in crystallinr lattice with each molecule bomded max to 4 partners. Water molecules are further apart to each other to form lattice causing ice to expand
Signifiance of lower ice density
During winter the whole ocean or lake dont freeze. This is bcs when water surface has freeze, it will form ice sheets that act as insulator. Organisms below it can survive
Why water principal solvent
It is a polar molecule that attracted to ions and other polar molecules. Attraction between wter and ions are stronger than ions and ions. Thats why NaCl dissolves redily in water
What happen when NaCl added into water
Water surrond the salt molecules and separate Na+ and Cl- by forming sphere of hydration and keeps ions dispersed in fluid
What does water form to separate Na+ and Cl-
Sphere of hydration
Solutes+solvent=aqueous solution
What is the function of aqueous solution
Medium for chemical reaction
Transport medium in organisms
Dissociation of water molecules
2H20=H3O+( hydronium ion)+ OH-(hydroxide ion) occasionally
H2O= H+ +OH-
Reversible and rare statistically
H and hydroxide ions are so reactive
Changes of both concentration can affect chemistry of cell
Most biological fluid pH is 6-8
Small change in pH shows substantial change in conc of these ions
Define acid and base
Acid is substance that increase [H+]
Base is substance that reduce [H+]
When HCl is added into water, it will dissociate form cl- and H+
Some base reduce [H+] directly, some indirect
How base direct and indirect
Direct by just accept the H+
Indirect by dissociate into cation and OH- then OH- combine with H+ to form water
Chemical process can be distrupted by changes of [H+] and [OH-] from normal values.To maintain pH we need what in our body
Buffer (buffer is specific for pH only)
Function of buffers
Minimize change in pH when acid or base is added. It can both accept or donate H+ depends on the concentration of H+. Typically consist of weak acif and its corresponding weak base
Example of buffer
Carbonic acid (pastu gi tengok equation dia) fahamkan aku tak reti buat
Mineral salts
Required in small quantity
Used to regulate body process
Minerals not store in body except iron
3 properties of carbon
Able to form 4 covalent bond
Has high affinity to other C atom
Can form multiple bonds with C,O,N (strong bonds)
C able to form 4 covalent bonds allow what
C atom to form diverse molecule by bomding with 4 other atoms
C has high affinity to C atoms allow
Formation of C skeleton (chain or ring)
Other element like H N O P will bind to C skeleton
What is hydrocarbon
Molecules consist of H and C only
Hydrocarbon is major comp of
Fats and petroleum
Hydrocarbon is hydrophobic bcs
Has many non polar C to H bond
What is isomers
Molecules with same molecular formula but diff structural formula and properties
What is the three types of isomer
Structural isomers Geometrical isomers (steroisomers) Optical isomers (stereoisomers)
C forms multiple bond with C O N . The bond form is
Strong bonds
May be 1 pair, 2pairs or 3
What is functional group
Cluster of atoms that are covalently bonded to carbon skeleton and give the organic compound diff properties
Parts of molecules that involve in chem reaction
(Tcr noor dulu kata tempat berlaku reaction)
6 example of functionaal group and its properties
Hydroxyl group OH polar
Amino group NH3+ charged
Carboxyl group COOH- charged
Carbonyl CO polar
Phosphate group PO3- charge
Sulfhydryl group SH polar
Functional group that is acidic
Carboxyl
Phosphate
Functional group that is basic
Amino
Diff position of functional group produce
Diff type of compound
What is polymers
Long molecule consist of many similar identical building blocks calle monomers linked by covalent bond
What is its polymers
Sugar
Fatty acids
Amino acids
Nucleotides
Polysaccharides
Lipids
Protein
Nucleic acid
Monomers linked together formed polymers by
Condensation (water removal)
What happen in condensation
Enzyme remove H+ from one monomer and OH- from another monomer to release water
Polymers breakdown through what
Hydrolysis (add water)
What happen in hydrolysis
H+ and OH- from water attached to the exposed site of polymers to break down it
protein is the most diverse biomolecule. State the roles of protein.
made up the phospholipid bilayer, production of enzyme, circulating hormones, antibody
amino acids consist of;
amino group, carboxyl group, hydrogen atom and R group
properties of amino acid scan be determined by the R group. it may be…
nonpolar/polar/positively charged/negatively charged
why do amino acids can act as buffer and form bipolar molecule when dissolved in water?
amino acid is an amphoteric molecule.
what are peptide bonds, its function and how did it form?
a covalent bond that links amino group of an amino acid to a carboxyl group of another amino acid through condensation.
gene(DNA) determines the sequence of amino acids. what does amino acids sequence determine?
the final shape of proteins
proteins need to reach its conformation to be functional. states the level of protein structures
primary structure
secondary structure
tertiary structure
quaternary structure
explain primary structure
unique sequence of amino acids of a polypeptide chain
explain secondary structure
regular, repeated folding of polypeptide chain
due to H bonds form between N – H group of one amino acid and C = O group of another
two types: alpha-helix and beta-pleated sheet
explain tertiary structure
- irregular folding of the polypeptide chain due to 4 types of bonds between side chains (R groups)
- three dimensional conformation of protein
- function of a protein depends on its tertiary structure
- if destructed it will lose its activity
explain quaternary structure
Interaction between more than one polypeptides in a single protein
what is the importance of primary structure?
Slight change in primary structure can affect a protein’s conformation and its ability to function
name the bonds between side chains(R group)
disulphide bonds(covalent bonds)
ionic bonds
hydrogen bonds
hydrophobic and van der Waals interaction
classification of proteins are based on the structure and composition. what is the characteristics for structure?
fibrous protein; no tertiary structure, long fibres or sheets is shape, insoluble in water, perform structural functions, length of polypeptide may varies
globular proteins; have tertiary structure, spherical in shape, dissolve in water, length of polypeptide chains always identical, perform metabolic function
what is the characteristics for composistion?
simple; contains only amino acids
conjugate; amino acids + non-protein molecule (prosthetic group)
denaturation is a process where protein lose its conformation. why does it happen?
Due to the bonds holding protein’s shape are broken
Factors that are able to break bonds:-extreme pH, excessive heat, chemicals, organic solvents, heavy metal ions
denaturation of proteins can be reversed using biotechnological methods but only for simple proteins. what is the process?
protein renaturation
