DLISC1 - WK6-9 Flashcards
(77 cards)
1
Q
what is environmental chemistry?
A
the study of chemical processes that occur in living environments, the effects of human activity on the environment
2
Q
what is a carbon footprint?
A
the amount of carbon dioxide (CO2) emissions associated with all the activities of a person of other entity
3
Q
what is the tradegy of the commons
A
a problem in which every individual has an incentive to consume a resource but at the expense of every other individual
4
Q
what are greenhouse gases?
A
a gas that contributes to the greenhouse effect by absorbing infarred radiation
5
Q
what is a fossil fuel?
A
a hydrocarbon-containing material formed underground as a reuslt of geologic processes acting on the remains of organic matter produced by photosynthesis in plants and decomposition of animals
6
Q
what is green chemistry?
A
is the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances
7
Q
basic chemistry
explain matter
A
- matter is used to describe objects that occupy space and have a discernible mass
- matter exists in threee major states: solids, liquids and gases
8
Q
basic chemistry
explain solids
A
have atoms arranged in fixed positions with definite shape and volume
9
Q
basic chemistry
explain liquids
A
have constant volume but do not take a definite shape. they assume the shape of their container
10
Q
basic chemistry
explain gases
A
- do not have definite shapae or volume
- gases contain the highest amount of kinetic energy
- freely moving
11
Q
basic chemistry
explain atoms
A
a basic building block of chemistry
- aotms can be any substance in the universe that has mass (weight) and occupies space, defined as matter
12
Q
explain the atomic composition
A
- protons: positively charged particles, location: nucleus
- Neutron: neutral particles, location: nucleus
- Electron: negatively charged particles, location: occupy space around nucleus (orbital)
13
Q
what is the atomic number?
A
the number of protons contained in the nucleus = number of p+
14
Q
what is the atomic mass?
A
determined by the presence of protons and neurons. electorns have negligible mass = nomber of p+ + number of n
15
Q
what are ions?
A
atoms in which the number of electrons does not equal the number of protons are called ions, and have an overall charge
- atoms that loos electrons are called cations, positively charged ions
- atoms that gain electrons are called anions, negatively charged ions
16
Q
what are isotopes?
A
forms of the same element that contain equal numbers of protons but different number of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties.
17
Q
what are the 4 types of chemical bonds
A
- metallic bond: positive metal ions attract conducting electrons
- ionic bonds: metal atom loses electorns to non-metal atom
- covalent bonds: two nonmetal atoms share electrons
- hydrogen bond: hydrogen attacks an electronegative aome electrostatically
18
Q
what are covalent bonds?
A
- involves the sharing of valence electrons between two non-metals
- the strength of the bond is determined by the number of electrons that are shared
19
Q
what are polar covalent bonds?
A
- Polar covalent bonds exist when electrons are unequally shared between atoms
- The unequal sharing of electrons is due to the differences in the electronegativities of the two atoms sharing the electrons
20
Q
what are non-polar covalent bonds?
A
- Is a chemical bond that is formed when electrons are shared equally between two atoms
- The number of electrons shared by the adjacent atoms will be the same
21
Q
what are metallic bonds?
A
- a force that holds atoms together by the sharing of electrons between metal atoms
22
Q
what is hydrogen bonding?
A
- An attraction between a hydrogen atom and a small electronegative atom
- Occurs when hydrogen is bonded to nitrogen, oxygen or fluorine
23
Q
what are chemical reactions?
A
- A process that involves rearrangement of the molecular structure of a substance
- A chemical reaction, is a process in which one or more substances, the reactants, are converted to one or more different substances, the products.
24
Q
what are the 5 types of chemical reactions?
A
- Combination or synthesis reaction
- Decomposition reaction
- Single-replacement reaction
- Double-replacement reaction
- Combustion reaction
25
describe combination or synthesis reactions
A combination reaction (also known as synthesis reaction) is a reaction in which two reactants combine to from one product
26
describe decomposition reactions
- Occurs when one reactant breaks down into two or more products
- Carbonic acid in soft drinks decomposes to give carbon dioxide gas
27
describe single replacement reactions
A reaction in which one element is substituted form another element in a compound
28
describe double replacemetn reactions
Occur when two parts of two ionic compounds are exchanged, making two new compounds.
29
desscribe combustion reactions
A reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat.
30
what is a catalyst?
- Is a substance that increases the rate of reaction without itself being consumed.
- Enzymes are naturally occurring catalysts responsible for many essential biochemical reactions.
31
what is an acid?
according to Arrhenius, the acids are the hydrogen-contining compounds which give H+ ions or protons on dissociation in water
32
what are bases?
ccording to Arrhenius bases are hydroxide compounds whivh give OH- ions on dissociation in water
33
what does pH stand for?
- power of hydrogen
- respresents the concentration of hydrogen ions in a water based solution
34
what is the pH scale?
- pH is exressed on a logarithmic scale
- pH = - log 10c
(c = concentration of H+ in moles perlitre)
- typically ranges from 0-14
- measures how acidic or basic a substance is
- substances with a pH less than 7 are acidic and will donate hydrogen ions
- substancces with a pH greater than 7 are basic/alkaline and will accept hydrogen ions
- for every 1 unit change, a 10-fold change in [H+]
35
what is the bronstead-lowry theory of acids and bases?
- A Brønsted-Lowry acid is any species that is capable of donating a proton H+ .
- A Brønsted-Lowry base is any species that is capable of accepting a proton, which requires a lone pair of electrons to bond to the H+ .
- Water is amphoteric, which means it can act as both a Brønsted-Lowry acid and a Brønsted-Lowry base
36
what is a strong acid and base?
is one that will almost completly dissociate or ionise to form ions in solution
37
three strong acids that we commonly find:
- hydochloric acid
- nitric acid
- sulfuric acid
38
two strong bases that are commonly found:
- sodium hydroxide
- potassium hydroxide
39
what are weak acids and bases
is one where only a small percentage of molecules will dissociate to form ion in solution
40
importance of acid-base regulation and health/disease outcome
when the human body is confronted with an excess of H2, ions form the diet, it emplys a number of strategies to main normal blood pH (7.4)
41
what is the biocarbonate buffer?
- physiological mechanism that maintains the acid-base balance in the blood and other body fluids.
- it regulates the levels of carbonic acid, bicarbonate and carbon dioxide to ensure proper physiological function
42
waht are buffers?
- A buffer is a solution that can resist pH change upon the addition of an acidic or basic components.
- a buffer is a substance that helps to stabilise changes in pH due to the addition of acid or base
- food and drink we consume have the ability to alter the acidity
43
what is acidosis?
- Acidosis is a condition in which the bodily fluids become too acidic, with an abnormally low pH level.
44
what is alkalosis?
is a condition in which the bolidy fulids become too alkaline, with an abnormally high pH level
45
symptoms of acidosis in the CNS
- headache
- shortness of breath
- confusion
- weakness
- vomitting
- sleepiness
- increased HR
46
symptoms of alkaosis in the CNS
- confusion
- hand tremor
- numbing or tingling
- twitching
- vomitting
47
what are enzymes?
- are proteins that help speed up chemical reactions in our bodies
- they build some substances up nad break down others
48
what are digestive enzymes?
enzymes produced in the digestive system
49
examples of digestive enzymes
- Lactase breaks down lactose
- Carbohydrase breaks down carbohydrates into sugars
- Lipase breaks down fats into fatty acids
- Protease breaks down protein into amino acids
50
what is organic chemistry?
- Is the study of the structure, properties, composition, reactions and preparation of carbon-containing compounds.
- contain carbon and hydrogen
51
what are the 4 macromolecules in life
- carbohydrates
- nucleic acid
- protein
- lipid
52
what are carbohydrates?
- are a nutrient that provides energy
- present in fruit, veggies, breads, grain products, sugar and sugary foods
- digested in the small intestine
- broken down into simple sugars such as glucose and fructose
- are used for energy or converted to glycogen for storage in the liver
53
carbohydrates - classification
- monosaccharides
- disaccharides
- polysaccharides
54
describe monosaccharides
- One saccharide (means sugar)
- Key chemical building blocks for making larger saccharides
55
describe disaccharides
- Two monosaccharides linked together by dehydration reaction
- New bond is formed, glycosidic bond (or linkage)
56
describe polysaccharide
- Long chains of monosaccharide units joined together through dehydration reactions
- The type of glycosidic bond leads to an array of different polysaccharides structures
57
saccharide derivatives
chemically modified sugars such as...
- glycoproteins
- glycolipids
- biomolecules
58
what are lipids
- a diverse group of organic compounds including fats, oils, hormones, and certain components of membranes
- One type of lipid, the triglycerides, is sequestered as fat in adipose cells, which serve as the energy-storage depot for organisms and also provide thermal insulation.
59
lipids - structure and function
- fatty acids
- triglycerides
- cholestrol
60
phospholipids - general structure
1. glycerol scaffold
2. two fatty acids atttached to glycerol backbone on one end
3. on the other end a phosphate group is attached plus a charged organic molecule linked to it
61
phospholipid bilayer
- More complicated structure where two layer from
- Hydrophilic heads point outward
- Hydrophobic tails point inward toward each other
62
what are nucleic acids
- a naturally occurring chemical compound
- capable of being broken down to yield phosphoric acid, sugars, and a mixture of organic bases
- are the main information carrying molecules of the cell,
- directs the process of protein synthesis, which determine the inherited characteristics of every living thing.
63
what are the two main classes of nucleic acids
- deoxyribonucleic acid (DNA)
-ribonucleic acid (RNA).
64
what is DNA
- DNA is the master blueprint for life and constitutes the genetic material in all free living organisms and most viruses.
65
what is RNA
- RNA is the genetic material of certain viruses, but it is also found in all living cells
- it plays an important role in certain processes such as the making of proteins
66
nucleic acid are...
nucleic acid are polymers of nucleotide subunits
67
nucletodie structure (monomers)
- ribose sugar (5 carbons)
- phosphate (C5')
- nitrogenous base (C1')
68
nucleotide structure of nitrogenous bases
adenine - A
guanine - G
cytosine - C
thymine - T
69
polyneucleotides
are neucleotdies linked together via a phosphodiester bond to from polyneucleotides
70
what is Chargaff's rule?
- Amount of adenine = amount of thymine
- Amount of cytosine = amount of guanine
71
organisation of DNA
- DNA is stored in a condensed, complex from
- Wraps around histones to from nucleosomes
- DNA uses the language of 4 neucleotide (A, G, T and C)
72
difference between RNA and DNA
RNA similar to DNA except
- contians ribose instead of deoxyribose
- contains uracil istead of thymine
RNA is single stranded
73
Classes of RNA
- messenger RNA
- Ribosomal RNA
- Transfer RNA
- Small nuclear RNA
- Small interfering (silencing) RNA
- microRNA
74
explain proteins
- Proteins are made up of amino acid subunit linked together to from a chain – polypeptide
- Variable in size
- Shape of a protein is determined by the amino acid composition
75
main purposes of proteins
defence
transport
support
motion
regulation
storage
76
protein structure
peptide bonds
amino and carboxyl end of AAs undergo a dehydation reactino, forming a covalent bond
77
levels of protein structure
primary structure: amino acid sequence
secondary structure: a-helices and B-(pleated) structure
tertiary structure: folding and packaging
quaternary structure: multiple polypeptide chain complexes
