Chapter 2 Flashcards
1
Q
What are the main chemical elements
A
Oxygen, carbon, hydrogen, nitrogen
2
Q
How many and what are the “lesser elements”
A
8 contribute to 3.6% of body masses
Calcium, Phosphorus, potassium, sulphur, sodium, chlorine, magnesium, and iron
3
Q
How many “trace” elements in the body
A
14 present in tiny amounts
4
Q
What are atoms ?
A
The smallest unit of matter that retain the properties and characteristics of the element
5
Q
What are the 3 subatomic particles that make up the structure of an atom ?
A
Small particles that compose individual atoms
1. Protons
2. Neutrons
3. Electrons
6
Q
What subatomic particles are contained in the nucleus of an atom
A
- Positively charged protons
- neutral/uncharged neutrons
7
Q
What are electrons ?
A
Negative charged subatomic particles that move around the nucleus of an atom
8
Q
What makes the atomic number of an element ?
A
The number of (-) electrons = the number of (+) protons
9
Q
What makes the mass number ?
A
The sum of protons + neutrons
These are within the nucleus
10
Q
What is an isotope ?
A
The same element with the same atomic number (same number of electrons to protons) but has a different number of neutrons within the nuclei causing a different mass number
11
Q
The number of electrons in an atom determines its ________?
A
Chemical properties.
This means whether it receives or donates their electrons to form a bond
12
Q
What is an ion?
A
When there are unequal numbers of protons and electrons causing a particle to have a positive (more protons) or negative charge (more electrons)
13
Q
What is ionization ?
A
Process of giving up or gaining electrons
14
Q
What is a molecule ?
A
When two or more atoms share their electrons
The molecule formulated indicates the elements (oxygen) and number or atoms (2 of them to = O2)
15
Q
What is a compound ?
A
Contains atoms of 2 or more different elements
(H20, two molecules of hydrogen and one of the element oxygen)
16
Q
What is a free radical?
A
An atom, molecule, or ion with an unpaired electron in the valence shell
17
Q
What is a valence shell ?
A
The outermost shell of an atom, where chemical bonds occur depending on the number of electrons there. This number identified whether it is required to donate or receive electrons
18
Q
What is an ionic bond ?
A
Force of attraction that holds together ions of opposite charges (opposites attract)
example: Na has an extra (1) electron alone in its valence shell that it dan donate
Cl has 7 in its valence shell, open to receive the excess electron to make it stable.
The giving away causes a +1 charge ion (cation) for its “extra” donated electron while the Cl become a -1 charge (anion) for having received 1 electron.
Na (+1) attracts the Cl (-1) to form the ionic bond
19
Q
What is an ionic compound ?
A
- When a compound (atoms of 2 or more different elements ex. NaCl) break apart into a positive or negative ion
- Known as an electrolyte when the compound is placed into a solution
- The electrons in the valence shell donate into a charge, and then attract to each other by ionic bond
Na+ + Cl- = NaCl
20
Q
What is a cation and an anion
A
Cation is a positive charge ion, anion is a negative charge ion
21
Q
What is a covalent bond?
A
When two or more atoms share their electrons (valence shell to become stable requires 8 electrons, they share by attaching multiple other atoms and their extra electrons till they contain 8 in the valence shell)
22
Q
What is a hydrogen bond?
A
attracts mainly fluorine, oxygen and nitrogen
unequally causes an unshared electron pair for these atoms to make them partially - charge and the
Hydrogen become partially + charged
23
Q
Why do hydrogen bonds work?
A
- ability for cohesion to link between molecules (like particles to stay together)
- has high surface tension
- a good solvent for ionic compounds as it can readily form hydrogen bonds with solutes creating electrolytes
24
Q
Define a chemical reaction
A
When new bonds form or old bonds break between atoms
By metabolism, a reactant forms or breaks down into new products
25
What is potential energy
Stored energy
26
What is kinetic energy
Energy in motion
27
What is chemical energy
A form of potential energy that is stored in the bonds of compounds and molecules
28
What is the law of conservation of energy
Energy cannot be created or destroyed, but it can be converted from one form into another
Energy from one to another generally releases heat
29
Differentiate between exergonic chemical reactions and endergonic chemical reactions
1. Exergonic reactions release more energy than they absorb (occur with breakdown or nutrients)
2. Endergonic reactions absorb more energy than they release (occur with building of body structures)
30
Particles of matter such as atoms, ions, and molecules have ________ energy
Kinetic
31
What is activation energy
The collision energy needed to break chemical bonds of reactants
Initial energy is needed to start a reaction.
The reactants absorb enough energy for chemical bonds to become unstable and for valence electrons to form new combinations.
The new binds begin to form, and energy is then release to their surroundings.
32
How does concentration and temperature influence the chance of a collision to occur in causing a chemical reaction
Concentration: more particles of matter in a confirmed space increases the chance of collision as there is greater pressure in the space to force particles closer together so the particles will collide more often
Temperature: increase in temperature by heat energy causes particles to move rapidly causing more of a forceful collision
33
What is the function of a catalyst in a chemical reaction
They are chemical compound that speed up a chemical reaction by lowering the activation energy needed for the reaction to occur.
They help properly orient colliding particles (organization and precision) to make a reaction happen
Too much requirement for activation energy by temperature or concentration can kill or damage body cells as they require more energy to be used as they are slow. Catalyst prevent this.
34
Define a synthesis anabolism reaction
2 or more atoms, molecules, or ions combine to form new and larger molecules
They are endergonic, absorb more energy than they release
A + B -> AB
35
Describe a decomposition catabolism reaction
Splitting up a large molecule into smaller atoms, ions or molecules.
Exergonic reaction, as the release more energy than they absorb
AB -> A + B
36
Describe an exchange reaction
Consists of both synthesis and decomposition reaction, they switch partners
AB + CD -> AD + CB
37
Describe an exchange reaction
A synthesis and decomposition reaction, where they switch partners
AB + CD -> AD + CB
38
Describe a reversible reaction
Certain conditions are required to revert products to their original reactant
AB <—> A+B (example: can break down into A+B by adding water or combine to form back into AB with heat)
39
Describe the oxidation-reduction reaction
Oxidation: Loss of electrons, the oxidized substance releases energy
Reduction: gaining electrons, the reduced substance gains energy
The combination: these occur at the same time
40
Differentiate inorganic compounds from organic compounds
Inorganic compounds: lack carbon molecules, are simple structures, have few atoms, and can be an ionic or covalent bind
Organic compounds: do contain carbon molecules and hydrogen, they can only bond covalently
41
Water is an important and abundant __________ ________
Inorganic compound
42
What makes water important for all living systems
- Chemical reactions occur in watery substances
- water polarity (uneven sharing of valence electrons) makes it a great solvent for other ionic or polar substances
- water molecule cohesion (sticks together)
- resistant to temperature changes
43
What is a solution, solvent and solute
Solvent- substance that dissolves another substance (solute)
Solute- the substance that gets dissolved but the solvent
Solution- the substance that gets created by the solvent dissolving the solute
44
Water as a solvent occurs because
Waters has polar covalent bonds that allow its molecules to interact with other ions or molecules,
it’s a great solvent for ionized (charged) solutes or polar covalent substances as they are hydrophilic and can dissolve (break apart) easily in water
45
Water as a medium for chemical reactions works by:
Hydrolysis (during digestion, breaks down large molecules into smaller molecules by adding water)
or
dehydration synthesis reactions (2 small molecules join and form a larger molecule with water as another product?
46
Water as a lubricant is necessary for
Encouragement movement
Mucous for moistening food to slide down the digestive system
Serous fluid within the body cavities so internal organs can touch and slide over one another
Synovial fluid in joints so bones, ligaments and bending s can rub against each other without friction
47
Water and heat importance
Water can absorb and release large amounts of heat while maintaining its own temperature.
It has high heat capacity due to its large number of hydrogen bonds in water
As water absorbs heat energy, some is used to break hydrogen bonds, then less energy is left to increase the motion of waters molecules to increase the temperature
48
Water also has high heat vaporization which is important for:
Cooling effect on the surface of the skin
49
When inorganic acids, bases or salts dissolve in water, they dissociate. This means:
They separate into ions, and become surrounded by water molecules
50
An acid is a substance that dissociates into one or more ________ and one of more ______ because the _____ is a single proton with a _____ charge making it a proton ________
Hydrogen ions (H+)
anions
H+
positive
donar
51
An base is a substance that dissociates into one or more ________ and one of more ______ because it _______ from a solution making it a proton _________.
Hydroxide ions (OH-)
Cations
Removes H+
Acceptor
52
A salt when dissolved in water dissociated into _________. In the body, salts are ________ that carry electrical currents for nerve and musical tissues. The ions of salts provide chemical elements in ______ and ______ fluids of tissues.
Cations and anions
Electrolytes
Intracellular and extracellular
53
Acids and bases react with one another to form
Salts
54
What is a mixture?
Differentiate from solutions, colloids and suspensions
A mixture of elements, or compounds that blend together but do not become chemical bonded.
A solution remains evenly dispersed among the solvent molecules. The solute particles are very small which makes light scatter easily through to make the solution transparent
A colloid is the same, but the particles are larger, making the solution appear opaque
A suspension will mix together for a period of time but eventually settle out separating the contents
55
What is the concept of pH
Ensures homeostasis of intracellular and extracellular fluids to have a balanced quantity of acids and bases
56
The more hydrogen ions (H+) dissolved in a solution makes it more
Acidic
57
The more hydroxide ions (OH-) in a solution makes it more
Basic/alkaline
58
A solutions acidity and alkalinity is expressed on the pH scale from 0-14, with a concentration of H+ moles/L. When when pH is below 7 it indicates a _________ solution meaning more ________ than ___.
Acidic
H+
OH-
59
A solutions acidity and alkalinity is expressed on the pH scale from 0-14, with a concentration of H+ moles/L. When when pH is above 7 it indicates a _________ solution meaning more ________ than ___.
Alkaline/basic
OH-
H+
60
What is the function of a buffer system
Maintains normal limits of pH of certain body fluid to maintain homeostasis
It converts strong acids or bases into weak acids or bases by removing or adding protons (H+)
61
Differentiate between strong acids/bases to weak acids/bases
Strong acids and bases ionize easily, so they can contribute many H+ and OH- into a solution to change pH drastically
Weak acids and bases do not ionize as much so they contribute fewer H+ and OH- and have less of an effect on pH
62
What is the carbonic acid-bicarbonate buffer system
Carbonic acid acts as a weak acid, the bicarbonate ion acts as a weak base. These compensate for excess of shortage of H+ to balance the pH
63
Organic compounds are large with unique characteristics and complex function, these include
Carbohydrates, lipids, proteins, nucleus acids, and ATP
64
Carbon forms large bonds with other carbon atoms to build many different organic compounds with unique structures and functions. Due to the larger size, some do not _______ in water, making them useful for building body structures
dissolve
65
Carbon has _ electrons in its valence shell. It bonds covalently with a variety of atoms and form rings and straight branches chains. The chains of carbon atoms in an organic molecule is called a:
4
Carbon skeleton
66
Many carbons are bonded by hydrogen atoms, called:
Hydrocarbon
67
Attached to carbon skeletons are functional groups which has:
Specific arrangements of atoms contains characteristic chemical properties on the organic molecule
68
Differentiate monomers and polymers
Polymer is a small organic molecule that combines into a very large molecule called macromolecules. It is formed by covalent bonding of many monomers
Monomers are identical or similar small building block molecules
69
What is the reaction that occurs with the joining of two monomers
Dehydration synthesis
A hydrogen atom (H+) is removed from one monomer and a hydroxyl group (OH-) is removed from the other to form a molecule of water (H2O)
Macromolecules like carbohydrates, lipids, proteins, nucleic acids are assembled in cells by this process
70
What is the building blocks of carbohydrates
Includes sugars, glycogen, starches and cellulose
Is the source of chemical energy for generating ATP to drive metabolic reactions
The carbohydrate deoxyribose is used as a building block for DNA
71
What 3 elements are found in carbohydrates
Carbon, hydrogen and oxygen
72
What are the three major groups of carbohydrates ?
1. Monosaccharides (simple sugar)- monomers used to build carbohydrates
2. Disaccharides (simple sugar) splits into smaller simpler molecules by hydrolysis
3. Polysaccharides - many glucose monomers linked to one another in branching chains, they are insoluble in water (glycogen)
73
Functions of carbohydrates
Source of chemical energy to generate ATP for metabolic reactions
Limited amount is stored as glycogen in the liver and skeletal muscles, and starches are formed from foods we eat.
The glycogen and starches (polysaccharides) can be broken down into monosaccharides through hydrolysis reactions
Example: glucose levels drop, liver cells break down the glycogen into glucose, release it into the blood for body cells, which breaks it down to synthesize ATP
74
Identify the different types of lipids and their functions
—Fatty acids: synthesize triglycerides and phospholipids to catabolize and generate ATP
—Triglycerides: (includes fats and oils) protection, insulation, energy storage
Phospholipids: lipid component of the cell membrane
—Steroids:
— cholesterol (component in cell membranes, precursor of other steroids such as:
—bile salts (needed for digestion and absorption of dietary lipids)
—Vit D (regulate calcium level in body, encourage bone growth and repair)
— adrenocortical hormones (regulate metabolism, resistance to stress, salt and water balance)
— sex hormones (stimulate reproductive functions and sexual characteristics)
—Eicosanoids:
— prostaglandins and leukotrienes (modify hormone responses, blood clotting, inflammation, immunity, stomach acid secretions, airway diameter, lipid breakdown, smooth muscle contractions)
Other lipids:
— carotenes (synthesize Vit A, an and acts as an antioxidants)
— Vit E (promote wound healing, prevent tissue scarring, contributes to normal nervous system structure and functions also acts as an antioxidant)
— Vit K (synthesis of blood clotting proteins)
— lipoproteins (transports lipids in blood, carry’s triglycerides and cholesterol to tissues, removed excess cholesterol from the blood)
75
Differentiate between saturated fatty acids and unsaturated fatty acids
Saturated fatty acids:
-single covalent bonds between carbon atoms of the hydrocarbon chain
- lack double bonds, each carbon atom of the hydrocarbon chain is saturated with hydrogen atoms
Unsaturated fatty acids:
- contains one or more double covalent bonds between carbon atoms of the hydrocarbon chain
- not saturated with hydrogen atoms
76
What is a triglyceride made of:
- single glycerol molecule and 3 fatty acid molecules
- 3 carbon glycerol molecules form the backbone
- the 3 fatty acids are attached by the dehydration synthesis reaction, one fatty acid to each carbon or the glycerol backbone
- bond is formed where the water molecule is removed
77
Differentiate fats from oils
Fats:
A triglyceride that is solid at room temperature, contains mostly saturated fatty acids that lack double bonds in the hydrocarbon chains, they are closely packed together causing it to solidify
Oils:
A triglyceride that is liquid at room temperature, contains mostly unsaturated fatty acids with one or more double bonds that prevent it from closely packing together and solidifying.
78
Identify the building blocks of proteins and each of their functions
- Large molecules that contain carbon, hydrogen, oxygen, and nitrogen, sometimes sulfur.
—Amino acids
(Monomers of proteins, has hydrogen atoms and 3 functional groups: amino group, acidic carboxyl group, and a side chain)
— peptides
(Covalent bond joining each pair of amino acids is a single peptide group, which is formed when a water molecule is removed by dehydration synthesis reactions)
— dipeptide
(When two amino acids combine)
— tripeptide
(Adding another amino acid to a dipeptide)
—polypeptide
(Further additions forming a chain like peptide
— enzymes
(Catalysts that speed up chemical reactions, consists of two parts: protein portion called apoenzyme, and a nonprotein portion called cofactor)
79
What is the cofactor of an enzyme ?
May be a metal ion (iron, magnesium, zinc and calcium) or an organic molecule (coenzymes which are vitamins)
80
Oxidases are enzymes that is catalyzed by
Adding oxygen
81
Kinases is an enzyme that is catalyzed by
Adding phosphate
82
Dehydrogenases is an enzyme that is catalyzed by
Removing hydrogen
83
ATPases is an enzyme that is catalyzed by
Splitting ATP
84
Anhydrases is an an enzyme that is catalyzed by
Removing water
85
Proteases is an enzyme that is catalyzed by
Breaking down proteins
86
Lipases is an enzyme that is catalyzed by
Breaking down triglycerides
87
The main 3 properties of enzymes:
1. Highly specific (each enzyme binds only to specific substrates at an active site like a key-in-lock, OR, the active site changes it’s shape to fit snugly around the substrate)
2. Very efficient (catalyze reactions at rapid rates in comparison to reactions without these enzymes)
3. Subject to a variety of cellular controls (control by cell genes, they either enhance or inhibit the activity of a given al enzyme)
88
Enzymes lower the activation energy of a chemical reaction by _______ the randomness of the collision between molecules
Decreasing
89
Steps of the mechanisms of enzymes
1. Substrates makes contact with the active site (enzyme-substrate complex)
2. Substrate molecules are transformed by the rearranging/breakdown/combination of substrate molecules into products
3. The products move away from the enzyme, and the enzyme remains free for other substrates to attach
90
The roles of protein
1. Form structural framework
2. Regulate physiological processes, control growth and development
3. All shortening of muscle fibres, produces movement
4. Protect body against foreign substances and invading pathogens
5. Carry substances throughout the body
6. Act as enzymes to regulate biochemical reactions
91
Differentiate between DNA and RNA
DNA:
- nitrogenous bases (adenine, cytosine, Guanine, thymine)
-nucleotide sugar (deoxyribose)
- two stranded
- nitrogen base pairs (A-T, G-C)
- how is it copied ? Self replicates
- function: encodes information to make protein
- types: nuclear, mitochondrial
RNA:
- nitrogenous bases (adenine, cytosine, guanine, uracil)
- nucleotide sugar (ribose)
- one stranded
- nitrogen base pairs (A-U, G-C)
- how is it copied ? Uses DNA as a blueprint
- function: Carrie’s genetic code, assist making proteins
- types: Messenger RNA, transfer RNA, Ribosomal RNA
92
What is the functional role of ATP?
Energy currency if all living systems, it transfer the liberated energy in exergonic catabolic reaction to power cellular activities that require energy (endergonic reactions)
ATP + H2O -(ATPase)-> ADP + P + Energy
* water is added to ATP
* catalyzed by ATPase (hydrolysis)
* removal of a phosphate group creates ADP, and energy is liberated
ATP is limited, but the energy required is constant, and it need to be replenished
93
Function of ADP
Replenishes the supply of ATP
ADP+P+Energy-(ATPsynthase)->ATP+H2O
*the energy needed to attach a phosphate group to ADP is supplied by catabolism of glucose by cellular respiration in 2 phases
*1. Anaerobic phase: when oxygen is not required, glucose is partially broken down by catabolic reactions into pyruvic acid and 2 molecules of ATP
* 2. Aerobic phase: when oxygen is present, glucose in completely broken down into CO2 and H2O, generating heat and 30-32 ATP molecules
* the enzyme ATP synthase catalyzes the addition of a phosphate group to ADP
