The Chemistry Of Living Things Flashcards
What does the octet rule state?
Atoms prefer to have 8 valence electros
What is the reactivity of atoms when stable?
Low
What manes an atom stable
Fulfilling the octet rule, having 8 valence electrons
What is the reactivity of an unstable atom & why?
It is high because it wants to react to fulfill the octet rule
A covalent interractions/ bonds strong or weak?
Strong
What are weak interactions?
Non-covalent
What happens when non-covalent interactions occur in large numbers?
They create a cumulative effect
What are the 4 types of weak interactions that typically occur in organisms ?
Ionic interactions, hydrogen bonds, van de waals interactions & hydrophobic interactions
Definition of ionic interactions
Electrostatic interactions between charged particles
Where are ionic interactions strongest?
In a vacuum medium
Where are ionic interactions weaker? & why
In aqueous environments, water tends to separate the two charges making them further apart because water also interacts w/ the charges which makes then less attracted to each other
Where do ionic interactions typically occur is ex humans?
In amino acids
When do hydrogen bonds occur
When hydrogen is covalently bound to other atoms
Where do hydrogen bonds typically occur in biological systems?
In DNA base pairing
Definition of Van her waals interactions
Attraction between 2 uncharged atoms due to permanent/ transient/ induced dipoles
3 most common Van her walls interaction
Dipole-dipole, dipole-induced dipole & induced-dipole- induced-dipole
Definition of hydrophobic interaction
Intractor between non-polar molecules in an aqueous environment, exclusion g wall
4 Major bio molecule in organisms
Proteins, nuclei acids, carbohydrates/ polysaccharides & lipids
What are proteins?
Polymers built of monomer units called amino acids, chain of amino acids
What are some functions of proteins in the body & other organisms?
Muscle contraction, hormones, enzyme activity, storage, growth, repair etc.
When are proteins functional?
Only when they are put together in their proper structure & form
How many amino acid are there in the human body & how many are essential & non-essential? What does it mean you them to be essential or not?
20, 9 essential & 11 non- essential, essential have to be consumed & non- essential can be made by the body
What is it called when a Carbon has 4 differs bonds to it?
Chiral center
What do all amino acids have in common when looking at the chem of it
They all have a central Carbon, amino group, carboxyl group, they only differ in their R group
What is 2 units of amino acids connected called?
Dipeptide
What is 3 units of amino acids connected called?
Tripeptide
What is a chain of amino acids connected called when there are more than 10 units?
Polypeptide
What kind of bonds do amino acids make? & what is typical connected to what?
Peptide bonds, typically carboxyl group connected to amino group
What are the ends of an amino acid called?
End w / carboxyl group is C terminus end w/ amino group is N terminus
What end are chains of amino acids read from & to?
From N terminus to C terminus
What are the 4 kinds of protein structures?
Primary ( amino acid sequence) secondary structure ( alpa- helix / beta - plated sheets) tertiary structure (3d) & quatenary structure ( multiple polypeptides )
What protein structure is the only fully functional?
Quaternary structure
What are the two types of nuclei acid?
DNA & RNA
What kind of monomers are nucleic acids composed of?
Nucleotides
What is the back bone of DNA called?
Phosphate sugar backbone
What are the two types of pentuse sugar in nuclei acids
Ribose (RNA) & deoxirisose (DNA)
What are the 3 chemical components of nucleic acids?
Nitrogenous, pentose sugar, phosphate
What chemical group are the basepairs in DNA double helix?
Nitrogerous
What are the different types of nitrogenous base pairs & what defines them
Purine ( 2 nitrogenous rings, adenine & guanine), pyridines (only has 1 ring, thymine (DNA), cytosine & uracil(RNA))
What 3 elements do carbohydrates consist of?
Oxygen, hydrogen & Carbon
What is the simplest form of carbohydrates?
Monosaccharides
What are the 2 main functions of carbonhydates?
Energy & storage of energy
What can monosaccharides form & how?
Disaccharides & polysaccharides Via glycosidic bonds
What are some common disaccharides?
Sucrose ( glucose+ fructos), lactose ( glucose + galactose) & maltose (glucose+glucose)
What are some common polysaccharides & their main function?
Celulose, starch & glycogen (storage of energy)
What are lipids
A diverse group of bio molecous that are insoluble in water
What are enzymes?
Biological catalyst which speeds up the chemical reaction but is not consumed by the reaction. Most are proteins
How do reactions in the body start?
Spontaneously, they don’t need a catalyst to happen but just to speed the reaction up
Primary ways to increase reactions in body
Temperature & enzymatic catalyst
How much does enzymes speed up reactions?
10^5 - 10^7
Do enzymes increase the number of products?
No, only the speed
What does enzymes cover?
Activation energy / Ea
Do enzymes change the position of the equilibrium?
No, only the rate
What are enzyme inhibitors?
Compounds that bind to the enzymes & lower enzymatic activity
Examples of enzyme inhibitors
Drugs & toxins
Common types of reversible inhibition (name 4)
Competitive inhibition, pure non-competative inhibition, mixed non-competitive inhibition & allosteric/ uncompetitive inhibition
How do competitive inhibitors work?
They resemble normal substrates (what is meant to react w/the enzyme) & binds to the active site on the enzyme. Binding of inhibitor or substrate is exclusive. Concentration increases the chances of the inhibitors binding instead of the substrate
What is the difference between competitive & non- competitive inhibitors?
Competitive binds to active site where non -competative binds away from it.
Can both non- competitive inhibitor & substrate bind to enzyme at the same time?
Yes
Difference between pure & mixed non-competitive inhibitors
Pure binds far from activation site & changes enzyme conformation
Mixed binds close to activation site & affects the affinity of the enzyme for the substrate
When does uncompetitive inhibition occur?
When inhibitors bind to the enzyme-substrate complex (Es)
What are allosteric enzymes?
Effector molecules, can effect positively (activators) or negatively (inhibitors)
What are the 2 sites on enzymes?
Active site & regulatory site
What factors can effect enzymes?
Temp & pH
What are cofactors?
Non-protein part of enzyme needed for reaction to take place
Name common cofactors
Nad ( nicotinamide adenine dinuleotide), folic acid & vitamin c
What is anabolic process?
Building of larger molecules from smaller ones
What is lost when making monomers into polymers?
Water, so if 5 monomers are connected 4 h2o molecules are lost
Is water polar or non-polar?
Polar
What kind of bonds does water molecules form with other water molecules?
Hydrogen bonds
Why is water essential for life?
Good solvent: can dissolver molecules
Ice is less dense than water which allows for aquatic life
High heat capacity making it hard to heat up allowing for life to withstand changes in temp
Biological reactions take place in water
Cohesion of water molecules allows water to stick together which is important for water to move upwards in plants
Why does water have a high heat capacity?
Hydrogen bonds requiring more energy to brake
What is the latent heat of vaporization? & why is it relevant to biology
The amount of heat that must be transferred to a liquid substance at it’s boiling point to turn into gas
It allows for cooling when sweating
Does water have high or low heat of vaporization?
High
Does water have high or low specific heat capacity?
High
In what form is water most dense?
Liquid
What is a condensation/dehydration reaction?
Synthesis reaction
What happens during a condensation/dehydration reaction?
2 reagents combine covalently
Water is released: one water molecule is released for every bond formed
Requires enzymes to catalyse
What is a hydrolysis reaction?
Decomposition reaction
What happens during a hydrolysis reaction?
A bond is broken to yield 2 products
Water is used to brake the bond: one water molecule can break 1 bond
Require enzymes
How does a phosphorylation reaction go?
Add a phosphate Pi to a molecule (conecently) to give extra 2 negative charges
What enzymes perform phosphorylation?
Kinases
Where is the only place kinases work?
Inside the cell as ATP is required for phosphorylation to take place
What is the reverse of phosphorylation called?
Dephosphorylation
What happens in dephosphorylation?
A phosphate group is removed, removes the -2 charges
What enzyme is used for dephosphorylation?
Phosphates ( & water)
Is the phosphate removed during dephosphorylation added back to ATP?
No
Is Nadh → nad+ an oxidation or reduction?
Oxidation
Is nad+ → nadh an oxidation or reduction?
Reduction
What processes add carbon dioxide to the atmosphere
Combustion, aerobic respiration (both plants and animals) and the activity of decomposers
What processes remove carbon dioxide from the atmosphere
Photosynthesis
What processes add oxygen to the atmosphere
Photosynthesis
What processes remove oxygen from the atmosphere
The activity of decomposers, combustion, and aerobic respiration (in both plants and animals)
What is catabolism ?
Breaking apart a molecule, typically to release energy
What is anabolism?
Taking 2 smaller molecules & making a bigger molecule out of them. Uses energy
What is gluconeogehesis? & where does occur
Process where body produces glucose from non-carbohydrate sources such as amino acids, lactate & glycerol
Primarily in liver & to lesser extent in the kidneys
Name for breakdown of glycogen
Glycogenolysis
