Chapter 2: The Chemical Level of Organization Flashcards
List the main chemical elements of the human body
The science of the structure and interactions of matter
Chemistry
Matter
Anything that occupies space and has mass; made up of chemical elements
Mass
The amount of matter in any object, which does not change
Weight
The force of gravity acting on matter; this can change
Three states of matter
solids, liquids and gas
Chemical Elements
Make up all forms of matter, living and non-living.
There are 118; 92 are naturally occuring
How many chemical elements are normally present in your body?
26
Name the 4 major elements that constitute approximately 96% of the body’s mass
oxygen (O)
carbon (C)
hydrogen (H)
nitrogen (N)
Name the 8 lesser elements that contribute to about 3.6% of the body’s mass
Carla Plays Poker So She Can Make Ingenious <wins></wins>
Calcium (Ca)
Phosphorus (P)
Potassium (K)
Sulfur (S)
Sodium (Na)
Chloride (Cl)
Magnesium (Mg)
Iron (Fe)
What is the term for the remaining elements that make up 0.4% of body mass
Trace Elements
Eg Iodine
Three categories of elements
- Major Elements
- Lesser Elements
- Trace Elements
The smallest units of matter that retain the properties and characteristics of an element
Atom
These make up atoms
Subatomic Particles
3 types of subatomic particles
Proton, neutron, and electrons
Nucleus of an atom
The dense central core
Where are protons, p+, and neutrons, N0, found within the atom
The nucleus
Where are electrons, e-, found in an atom?
How do they move?
They move about in a space surrounding the nucleus
Form a ‘cloud’ around the nucleus and do not move in a fixed pathway
Certain regions around the nucleus that specific groups of electrons are most likely to move about within. Each one of these can hold a specific number of electrons.
Electron Shells
How many electrons does each electron shell hold?
First (closest to nucleus) = max 2
Second = max of 8
Third = max 18
Atomic Number
The number of protons within an atoms nucleus
Mass Number
The sum of an atoms protons and neutrons
Sodium has 11 protons and 12 neutrons, what is it’s atomic number and it’s mass number?
Atomic number is 11
Mass number is 23
Isotopes
Atoms of an element that have different numbers of neutrons and therefore different mass numbers
Identical chemical properties because they have the same number of electrons
Radioactive Isotopes
Unstable isotopes; these atoms have a nuclei that will decay to a stable configuration and will emit radiation (either subatomic particles or packets of energy) and often will turn into a different element
The time required for half of the radioactive atoms in a sample of an isotope to decay into a more stable form
Half-life
Atomic Mass
The average mass of all of an elements naturally occuring isotopes; usually close to most abundant isotope
Ion
An atom that has a positive or negative charge because it has unequal numbers of protons and electrons
Ionization
The process of giving up or gaining electrons
Molecule
When two or more atoms share electrons
Compound
A substance that ocntains atoms of two or more different elements
Free Radical
An atom of group of atoms with an unpaired electron in it’s outermost shel
Makes it unstable, highly reactive and destructive to nearby molecules
The forces that hold together the atoms of a molecule or compound
Chemical Bonds
Valence Shell
An atoms outer most shell; likelihood of chemical bonds occuring depends on the number of electrons in this shell
Octet Rule
One atom is more likely to interact with another atom if doing so will leave both with eight valence electrons; can donate, take or share electrons
Name three types of chemical bonds
Ionic
Covalent
Hydrogen
Positive and negative charged ions are attracted to one another and can create this type of chemical bond
Ionic Bonds
Cation
A positively charged ion (loses electrons and therefore has more protons)
Anion
A negatively charged ion (gains electrons and therefor has more electrons)
Electrolyte
An ionic compound that breaks apart into positive and negative ions in solution
When two or more atoms share electrons rather than gaining or losing them, a _________________ bond is formed. The more electrons shared between them, the stronger the bond
Covalent Bond
- most common bond in the human body
- can be the between atoms of same or different elements
Covalent bond numbers
Single - one pair shared
Double = two pairs shared
Triple E three pairs shared
Nonpolar Covalent bonds
when two atoms share the electrons equally, eg between two atoms of same element
Polar covalent bond
Sharing of electrons is unequal, the nucleus of one atom attracts the shared electrons more strongly than the nucleus of the other atom
Electronegativity
When polar covalent bond forms, the atom with the stronger pull on the electrons has a partial negative charge and has greater electronegativity
An important polar covalent bond in living systems
H20 The bond between hydrogen and oxygen
Polar covalent bonds that form between hydrogen atoms and other atoms
Hydrogen Bonds
How does a hydrogen bond form?
When a hydrogen atom with a partial positive charge attracts the partial negative charge of neighboring electronegative atoms
What type of bond forms because of attraction of oppositely charged PARTS of molecules rather than sharing of electrons or donating/taking electrons
Hydrogen Bonds
Bond that cannot bind atoms into molecules; weakest bond;
Hydrogen Bonds
Surface Tension
Caused by hydrogen bonds of water molecules and measures the difficulty of stretching or breaking the surface of a liquid
Chemical Reaction
When new bonds form or old bonds break between atoms; interactions of valence electrons are basis of all chemical reactions; involves energy changes
Metabolism
All chemical reactions occuring in the body
Reactants
Starting substances
Products
ending substances
What are the two principle forms of energy?
Potential and kinetic
Potential Energy
Energy stored by matter due to its position
Kinetic Energy
The energy associated with matter in motion
Law of conservation of energy
Total amount of energy remains the same; it cannot be created nor destroyed, but can be converted from one form to another
Chemical Energy
a form of potential energy that is stored in the bonds of compounds and molecules
Exergonic Reaction
A chemical reaction that releases more energy than is absorbed
Endergonic Reaction
A chemical reaction where more energy is absorbed than is released.
Activation energy
The collision energy needed to break the chemical bonds of a reactant; needed to start a reaction because it causes enough energy to be absorbed that their chemical bonds become unstable and new combinations begin to be formed
The more particles of matter present in a confined space, the greater the chance they will collide
Concentration affects reactions
As temperature increases, the particles of matter move more rapidly, increasing likeliness of more forceful collisions and therefore more likely the collision will produce a reaction
Temperature affects reactions
Chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur. Eg enzymes
A catalyst
Synthesis Reactions - Anabolism
When two or more atoms, ions or molecules combine to form new or larger molecules. Usually energonic.
Decomposition Reactions - Catabolism
Split up larder molecules into smaller atoms, ions or molecules. Usually exergonic.
Exchange reactions
Reactions that consist of both synthesis and decomposition reactions
Reversible reactions
the products of a reaction can revert to the original reactants (indicated by two half hours pointing in opposite directions)
Oxidation-Reduction Reactions
Important in breaking down food molecules and producing energy
Oxidation - loss of electrons where oxidized substance releases energy
Reduction - gain of electrons, the reduced substance gains energy
Compounds that usually lack carbon and are structurally simple. Eg water, salts, etc. ionic or covalent bonds.
Inorganic compounds
What percentage of a lean human body does water make up?
55-60%
Other inorganic matter makes up about 1-2%
Inorganic compounds that contain carbon are:
Carbon Dioxide
Bicarbonate
Carbonic Acid
Compounds that always contain carbon, usually contain hydrogen and always have covalent bonds
Organic Compounds
What percent of the lean body is made up of organic compounds?
38-43%
The most important and abundant inorganic compound in all living systems
Water
The most important property of water
It’s polarity
Solution is made up of:
Solvent that has dissolved a solute
Solutes that are charged or contain covalent bonds are
Hydrophillic
Molecules that ocntain mainly nonpolar covalent bonds
Hydrophobic (not very water soluble)
Hydrolysis
The breakdown of large nutrient molecules into smaller molecule by adding water molecules that takes place during decomposition reactions
When two smaller molecules combine to form a larger molecule and a water molecule is one of the products formed
Dehydration synthesis reaction
Three types of mixtures (mixed together but not bound by chemical bonds)
Solution - transparent
Colloid - opaque from larger molecules
Suspensions - suspended material will settle out
Moles per liter (mol/L)
molarity; total number of molecules in a given volume of solution
Percentage (mass per volume)
Number of grams of a substance per 100ml of solution
When inorganic acids, bases or salts dissolve in water and seperate into ions, becoming surrounded by water molecules
dissociate
Acids
Has more H+ than OH- molecules; pH below 7
Disocciate in water into one or more H+ (hydrogen) ions and one or more anions
(proton donor)
Bases
Has more OH- than H+ molecules ; pH above 7
Disocciate into one or more hydroxide ions (OH-) and one or more cations
(proton acceptor)
When added to water, these dissociate into cations and anions, neither of which are H+ or OH-
Salts
The measure of a solutions acidity or alkalinity is expressed using this scale which is based on the concentration of H+ in moles per liter
pH scale
What is the normal pH of the blood
7.35-7.45 slightly more basic than water
These function to convert strong acids or bases into weak acids or bases by adding or removing protons H+
buffer systems
Carbonic acid-bicarbonate buffer systen
This buffer system is important in maintaining homestatic pH levels in the body
What bond are organic compounds usually held together with?
Covalent
Elements that commonly bond with carbon in organic compounds
hydrogen, oxygen, and nitrogen
Some sulfur and phosphorus
The chain of carbon in an organic molecule
Carbon Skeleton
When many carbons are bonded to hydrogen atoms
Hydrocarbon
Functional Groups
Atoms or molecules bound to the hydrocarbon skeleton. Each type of functional group has a specific arrangement of atoms that confers characteristic chemical properties on the organic molecule it it attached to
When small organic molecules combine into very large molecules
Macromolecules; usually polymers;
What is a polymer?
A polymer is a large molecule formed by the covalent bonding of many identical or similar small molecules called monomers
Dehydration Synthesis
When two monomers join through reaction by the removal of a hydrogen atom from one monomer and a hdroxyl group for the other, this forms a molecule of water
Molecules with the same molecular formula but different structures and therefore different chemical properties
eg. glucose and fructose
Isomers
Sugars, glycogen, staches, and cellulose
Carbohydrates “watered carbon”
Three major groups of carbohydrates
(2-3% of total body mass)
Monosaccharides
Disaccharides
Polysaccharides
“Simple Sugars”
Mono and di saccharides
- The monomers of carbohydrates
- contain 3-7 carbon atoms
- ‘ose’ name with prefix for number of carbons eg. Triose to heptose
Monosaccharides
Hexose Glucose
- broken down by body to produce ATP
A molecule formed from the combination of 2 monosaccharides by dehydration synthesis (producing also a water molecule).
These can be broken back down into their monosaccharides by adding a water molecule
Disaccharide
Contains tens or hundreds of monosaccharides joined through dehydration synthesis reactions
Insoluble in water
do not taste sweet
Polysaccharides
Main polysaccharide in the human body
Made up of glucose monomers linked to one another in branching chains
Stored in liver and skeletal muscles
Glycogen
Major carbohydrates in the diet
Found in pasts and potatoes
Formed from glucose by plants
Starches
A polysaccharide produced by plants that cannot be digested by humans but does provide bulk to helpe eliminate feces
Cellulose
Organic compound that makes up 18-25% of body mass
Contain hydrogen, carbon and ocygen
Fewer polar covalent bonds than carbohydrates due to lower numbers of electronegative oxygen
Hydrophobic; not soluble in in polar solvents
Lipids
How do small lipids become more soluble in blood plasma?
They join with hydrophyllic proteins to form lipoproteins
Lipoproteins are soluble because…
The water soluble protein is on the outside of the complex and the lipids are on the inside
Some types of lipids
Fatty acids
triglycerides,
steroids,
phospholipids
eicosanoids (20 carbon lipids)
fat soluble vitamins (A, D, E, K)
lipoproteins
and more
These are used to synthesize triglycerides and phospholipids
The simplest of lipids
Consists of a carboxyl group and a hydrocarbon chain
Can be catabolized to generate ATP
Fatty acids
This fatty acid contains only a single covalent bond between the carbon atoms of the hydrocarbon chain. Each carbon is saturated with hydrogen atoms
saturated fatty acids
These fatty acids contain one or more double covalent bonds and are not completely saturated with hydrocarbon atoms
Unsaturated Fatty Acids
The most abundant lipids in the human body and diet
Triglycerides
What are the two types of building blocks that make triglycerides?
A single 3-carbon glycerol molecule (backbone of the triglyceride)
3 fatty acids (one attached to each carbon through dhydration synthesis)
triglyceride that is solid at room temperature
A fat
What is a saturated fat
A fat that mainly consists of saturated fatty acids. Because of the lack of double bonds the y can closely pack together forming a solid at room temp
Where are saturated fats mostly found?
Meats, but also palm oil, cocoa butter and coconut oil
What is a triglyceride that is liquid at room temperature?
Their fatty acid are mostly unsaturated
An oil
Two types of fatty acids in oils that are believed to reduce the risk of heart disease
Monounsaturated - olive oil, peanut oil, canola oil, nuts, avocados
Polyunstaurated - corn oil, fatty fish, etc
What is the body’s most highly concentrated form of chemical energy?
These provide more than twice the energy as carbohydrates and proteins
Triglycerides
What are excess carbohydrates, protein, fats and oils stored as?
Triglycerides in the adipose tissue
This type of lipid has a 3 carbon glycerol, however only the first 2 carbons have a fatty acid chain attached and the third one has a phosphate group that links a small charged group that contains nitrogen to the backbone
Phospholipids
Describe the head of a phsopholipid and its tails
The head is the group containing nitrogen, it is polar, and can form hydrogen bonds with water molecules
The tails are the two fatty acids
Molecules that have both polar and non-polar parts are said to be ____________
amphipathic
How are phospholipids involvref in the membrane surrounding a cell
They line up tail to tail to form a double row that makes up most of the membrane that surrounds a cell
These lipids have 4 rings of carbon atoms
Steroids
This has a large nonpolar region consisting of 4 carbon rings and a hydrocarbon tail
Cholesterol
Lipids derived from 20-carbon fatty acids called arachidonic acid
Primarily prostaglandings and leukotrienes
Eicosanoids
These had a wide variety of functions. The modify responses to hormones, contribute to the inflammatory response, prevent stomach ulcers, dilate airways to the lungs, regulate body temperature, and influence the formation of blood clots, etc
Prostaglandins
These eicosanoids participate in allergic and inflammatory repsonses
Leukotrienes
These are large molecules that contain carbon, hydrogen, oxygen and nitrogen. Some may contain sulfur.
Much more complex than carbohydrates or lipids
Proteins
What percentage of a lean adult body is protein?
12-18%
Some common protein functions
- largely responsible for the structure of body tissues
- enzymes are proteins
- may work as motors to drive myscle contractions
- antibodies are proteins
- some hormones are proteins
What are the monomers of proteins? How many are there?
Amino Acids; 20
What makes up an amino acids?
Each one has:
1. Hydrogen atom
2. An acideic carboxyl group
3. A side chain (R group)
What gives each amino acid it’s distint chemical identity?
The different side chains
What is the name of the covalent bond that joins two amino acids?
A peptide bond
Where does a peptide bond always form?
What else is created?
Between the carbon of the carboxyl group of 1 acid and the nitrogen of the amino group of the second acid.
And H20 molecule is also formed and removed
What type of reaction breaks a peptide bond?
A hydrolysis reaction (adding an H20 molecule)
A dipeptide
2 amino acids combined
A tripeptide
3 combined amino acids
A chainlike peptide has how many amino acides?
4-9
How many amino acids are in a polypeptide?
10+
What is the process where a protein that encounters an altered environment unravels and loses its characteristic shape?
Eg heat to an egg cause irreversible ________ to the protein
Denturation
What are most catalysts in living cells?
protein molecules called enzymes
What is an apoenzyme and a cofactor?
Apoenzyme - a protein portion of an enzyme
Cofactor - a metal ion or organic molecule called a coenzyme (usually derived from vitamins)
What is the suffix of an enzyme name? Examples?
-ase
Anhydrase - removes water
proteinases - break down proteins
lipases - break down triglycerides
What are three important properties of enzymes?
- Highly specific - they only bind to specific substrates
- Very efficient - increase reaction rates to 100 million to 10 billion times the time without enzymes
- Have cellular controls - controlled by cells genes and activation of them are determined by chemical environment within cells
What is a substrate?
The reactant molecules on which an enzyme acts. Each enzyme can only bind with certain substrates.
What is the active site of an enzyme?
the part of the enzyme that catalyzes the reaction
May fit the substrate like a lock and key
or May change shape to fit snugly around the substrate (induced fit)
How does an enzyme work?
- enzyme-substrate complex created
- substrate molecule changed
- Enzyme unchanged
- Substrate makes contact with active site of enzyme; forms a temp compound “enzyme-substrate complex”
- Molecules of substrate transformed by breakdown of the mocule, rearrangement of existing atoms or combination of several substrate molecules
- Enzyme is unchanged and reusable
What do nucleic acids contain?
carbon, hydrogen, oxygen, nitrogen, phosphorus
What is DNA
Deoxyribonucleic Acid
forms inherited genetic material inside each cell nucleus
This is a segment of DNA molecules that determine the traits we inhereit and controls protein synthesis
Passed on with each cell division
Genes
What is RNA
Ribonucleic Acid
relays instructions from the genes to guide the synthesis of proteins from amino acids
Nucleotides
The monomers that make up a nucleic acid
What 3 parts does each nucleotide of a DNA consist of?
- Nitrogenous base
- Pentose sugar (deoxyribose)
- Phosphate group
What are the 4 different nitrogen bases in DNA?
A, T, C, G
Adenine
Thymine
Cytosine
Guanine
Which two nitrogen bases are purines and have larger double rings
Adenine and Guanine
Which two nitrogen bases are smaller, single ringed bases called pyrimidines
Cytosine and thymine
What is the DNA model called that resembles a spiral ladder?
Describe the visual
Double Helix Model
Two strands of alternating phosphate groups and deoxyribose sugars form the uprights of the ladder.
Paired bases held together by hydrogen bonds form the rungs
Which bases pair with which?
Adenine and thymine
Cytosine and Guanine
What is a change that occurs in the base sequence of a DNA strand that can results in the death of a cell, cause cancer or produce genetic defects in future generations?
A mutation
How does RNA differ from DNA in humans?
- single stranded
- the pentose sugar is ribose
- contains the pyrimidines bases Uracil instead of thymine
Name the 4 bases in DNA with their complement
AT, CG
Adenine and Thymine
Cytosine and Guanine
Name the 4 bases in RNA with their complement
AU, CG
Adenine and Uracil
Cytosine and Guanine
3 types of RNA
- messenger RNA
- ribosomal RNA
- transfer RNA
What uses the energy from exergonic catabolic reactions to power cellular activities that require energy (energonic reactions)
ATP
Adenosine Triphosphate
What are some examples of reactions ATP is used for
- muscular contractions
- movment of chromosomes during cell division
- movement of structures within cells
-transport of substances across cell membranes - synthesis of larger molecules from smaller ones
What is ATP (adenosine triphosphate) composed of?
Three phosphate groups attached to an adenosine
What is adenosine made up of?
Adenine and a ribose (5 carbon sugar)
How does ATP release energy?
When a water molecule is added to ATP, the third phosphate group is removed and energy is liberated
What enzyme catalyzes the hydrolysis of ATP?
ATPase
What is produced when the third phosphate group is removed from ATP through hydrolysis (adding a water molecule)?
Adenosine Diphosphate (ADP)
ATP + water With ATPase*
=???
ADP + Phosphate Group + energy
What enzymes helps replenish ATP when stores are low?
ATP synthase
ADP + Phosphate group + Energy with ATP synthase* =
ATP + water molecule
What role does the catabolism of glucose through cellular respiration play int he production of ATP?
This catabolism through cellular respiration provides the needed energy to attach a phosphate group to create ATP from ADP
What are the two phases of cellular respiration?
Anaerobis Phase
Aerobic Phase
Describe the anaerobic phase of cellular respiration
- no oxygen, glucose partially broken down into pyruvic acid
- 2 molecules of ATP produced from from each glucose molecule that is converted into pyruvic acid
Describe the aerobic phase of cellular respiration
- in presence of oxygen, glucose broken down completely into CO2 and water
- this creates heat and 30-32 ATP molecules
