Chapter 2 Chemical Principles Flashcards
Define Chemistry
The study of interactions between atoms
What type of chemistry is non-living?
What type of chemistry is living
Inorganic
Organic
Everything that occupies space is made of?
What is the smallest unit of matter that enters into chemical reactions?
Matter
Atom
Atoms interact to form what?
Molecules and compounds
What are atoms composed of?
Electrons (-)
Protons (+)
Neutrons neutral
What does the number of protons define?
What is the Atomic weight?
Atomic Number
Sum of the Protons and Nuetrons
Define Isotopes?
They are atoms with different number of NEUTRONS.
Ex. Isotopes of oxygen 16O, 17O, 18O
What are the elements of life?
hydrogen Carbon Nitrogen Oxygen Sodium Mg Phosphorus
How are electrons arranged? Meaning what is its names?
How many can each hold
Shells or orbits
Each can hold
- 2
- 8
- 8
- 18
What is the octet rule?
What is the exception?
Atoms react to one another to achieve 8 electrons in the outer shell
Hydrogen (H2)- the first shell which is complete with 2e is the outer shell
To comply with the octet rule what must atoms do?
The number of missing or extra electrons in this shell is known as?
Atom must combine to complete the outer most shell
Called valence
Molecules that hold together because the valence electrons of the combining atoms form attractive forces is called?
What is needed for this to happen?
Chemical bonds
These bonds need energy to form so each molecule had some potential energy
What are the three different chemical bonds
- ionic bonds - transfer of e-
- covalent bonds - Sharing of e-
- hydrogen bonds - weak bonds that can be broken and re-formed.
Example of Ionic Bond
NaCl
Sodium (donor) gives up an electron to chloride (electron acceptor)
What are ionic bonds
The number of protons and electrons is equal in an atom, so atoms have no net charge
Ions are charged atoms that have either gained or lost electrons
Attractions of the opposite charge is called?
Ionic Bonds are attractions between ions of opposite charge. One atom loses and electron and the other gains an electron
Negatively charged ions are called?
Positively charged ions are called?
Anions
Cations
The reason why ionic bond forms between Na and Cl
The opposite charge holds them together
Define covalent bonds?
They form with two atoms share one or more pairs of electrons
Example is Methane CH4
Define hydrogen bond?
They form when a hydrogen atom that is covalently bonded to an O or N atom is attracted to another N or O tame in another molecule
Define Molecular weight
The sum of the atomic weight in a molecule is the molecular weight
One ? Of a substance is its molecular weight in grams
Mole
What involves the making or breaking of bonds between atoms?
Chemical reactions
What is the change that occurs during a chemical reaction?
What are the two types of reactions and what do they do?
What is waters role?
Chemical energy
Endergonic reactions absorb energy
Exergonic reactions release energy
H2O is either produced or used in both reactions
Define Anabolism?
What else is this called?
What happens to energy with these?
Is the synthesis of large molecules in a cell
Dehydration or condensation
Usually use energy
Define Catabolism
Decomposition reactions in a cell and usually generate energy
What are exchange reactions?
Are part synthesis and part decomposition
What is the collision Theory?
What is this energy called?
All atoms, ions and molecule are constantly moving and colliding with each other
The Collision energy which is required for a chemical reaction is it’s Activation Energy (AE)
What is an enzymes function when it comes to a reaction?
What are enzymes made of?
Enzymes decrease AE and act as catalyst to speed up the reaction.
They are made of proteins
What does an enzyme primarily work on?
Do they work on all?
Enzymes work on substrates and enzymes are very specific.
What always contain carbon and hydrogen and are large like proteins,a no lipids?
Organic compounds
Inorganic lack carbon
Define water
Inorganic molecule
Polar molecule
Typically a solvent
Has a negatively charged pole and a positively charged pole.
Polar substances dissociate and dissolve in water which are called?
Hydrophilic
What is the significance of the hydrogen bonds of water
The H-bonds absorb heat
Makes water a temperature buffer
Define acids
What are they called?
Substances that dissociate into one or mor H+ (proton)
Therefore called proton donor
HCL —> H+ + Cl-
Define bases
What are they typically called
Substances that dissociate into one or more OH- (hydroxide ion), they accept H+
The are proton acceptors
NaOH—> NA+ + OH-
Define salts
Substances that dissociated into cations and anions, neither of which is H+ or OH-
The amount of H+ in a solution is expressed as?
What is the formula to calculate this?
- pH
- pH = -log10 [H+]
Increasing [H+] increases acidity
Increasing [OH-] increases alkalinity
Most organisms grow at what pH?
Give examples
Between pH 6.5 and 8.5
- Fungi. Acidic (pH <7)
- Cyanobacteria. Alkaline (pH>7)
What is the function of a buffer?
Resists the changes in pH and keep pH constant
What are macromolecules
What are the smaller unit molecules called?
Polymers consisting of many repeating unit organic molecules that combine to form large macromolecules
Monomers
How are polymers made?
Monomers join by dehydration, synthesis or condensation reactions to form macromolecules
Define carbohydrates
Energy sources and also cell structures
They are named according to the number of Carbons
- Hexose has 6 (C)
- Pentose has 5 (C)
What are the simple sugars with 3 to 7 carbon atoms
Monosaccharides
Define disaccharides and how they are broken down and give an example?
Disaccharides are formed when 2 monosaccharides are joined in a dehydration synthesis
They can be broken down by hydrolysis
E.g. Glucose + Galactose —> Lactose
What are Oligosaccharides
Consist of 2 to 20 monosaccharides
What are polysaccharides
Give a few examples of polymers of glucose
Consists of tens or hundreds of monosaccharides joined through dehydration syntheses
Starch, glycogen, dextran, and cellulose, are polymers of glucose that are covalently bonded differently
What is chitin
A polymer of 2 sugars repeating many times. the shells of crabs and lobsters
Define Lipids
Primary component of cell membranes
Consist of C, H, and O
Are non-polar and insoluble in water
What are considered simple lipids, meaning their structure and how they are formed?
Fats or Triglycerides
Contain 1 glycerol backbone and 3 fatty acid tails.
Formed by dehydration synthesis
When a fatty acid has no double bonds, what is it said to be and explain its structure
Saturated fat- no double bonds
They are solid at room temperature
What does it mean when a fat is said to be unsaturated?
What are the two forms unsaturated fatty acids can be?
Unsaturated fat has one or more double bonds in the fatty acids, and they are liquids at room temp
Cis: H atoms on the same side of the double bond
Trans: H atoms on the opposite side of the double bond
Define phospholipids?
What is the unique fact about them
Contain phosphorus, nitrogen and sulfur.
Membranes are made of phospholipids
The interesting fact is they have both polar and non-polar ends
Define Steroids & Cholesterol
4 carbon rings with an -OH group attached to one ring
They are also parts of membrane
Define proteins and give examples
Proteins come from genes and they are essential in cell structure and function
Enzymes are proteins that speed Chem reactions up
Transporter proteins move chemicals across membranes
Flagella (motility) are made of proteins
Some bacterial toxins are proteins
Structural proteins- They are the building blocks for muscle, hair, and nails
What are the two stereoisomers of Amino Acids
D or L (mirror) image
L-forms are the most often found in nature
What are the levels of protein structure and define them?
Primary Structure- the sequence of amino acids in a polypeptide chain
Secondary structure - occurs when the amino acid chain folds and coils in a regular helix or pleats
Tertiary- occurs when the helix folds irregularly, forming disulfide bonds, hydrogen bonds, and ionic bonds between the amino acids in the chain
- they are 3-D structures
- they do depend of temp and pH
- Therefore in a hostile environment they could denature
Quaternary- consists of 2 or more polypeptides in their folded state
What is a conjugated protein
Give the 4 main conjugated proteins
Proteins consists of amino acids and other organic molecules
- glycoproteins- sugar
- nucleoproteins- nucleotide
- lipoproteins- lipids
- phosphoprotein- phosphate
What are nucleic acids made of? And what do they form
Made of nucleotide subunits
Nucleic acids are made from genes
What are the two forms of nucleic acids and what is their difference?
DNA
RNA
They differ by an oxygen
the genes on DNA have a specific function, what is it?
Genes encode for proteins
What are the three parts of a nucleotide?
- Phosphate
- Sugar
- Nitrogen-containing base
How are the strands of DNA formed?
Nucleotides are linked via covalent bonds, which are between the phosphate of one nucleotide and the sugar of another and this continues in an alternating fashion. Sugar, phosphate, sugar, phosphate etc…
The alternating form of sugars and phosphates form what?
Form the back bone of DNA with the bases extended outward
What are the 4 bases found in DNA
Adenine
Thymine
Cytosine
Guanine
What are the purines of the nitrogenous bases?
Adenine
Guanine
What are the Pyrimidines of the nitrogenous bases
Thymine
Cytosine
What binds to what in base pairing? How many hydrogen bonds form?
A bind to T double bond
G bind to C triple bond
Sugars and phosphates for what? And base pairs form what in DNA?
Sugars and phosphates make up the sides of DNA while the linked base pairs form the rungs
What are the overall 5 bases found in nucleotides
Adenine and guanine which are double ringed purines
Cytosine, thymine and Uracil are single ringed Pyrimidines
Uracil is only in RNA
What is RNA and explain its structure and bonding capabilities
Ribonucleic Acid
It’s sugar is ribose
It’s single stranded
A hydrogen bonds to U
C hydrogen bonds to G
Who are the 4 scientists involved in the discovery of DNA and its structure
Watson and Crick
Rosalind Franklin and Maurice Wilkins
Define ATP, its structure and function
Adenosine triphosphate
Has ribose, adenine, and 3 phosphate groups
It’s the energy currency of the cells
