Chapter 2 Flashcards
Chemical elements
Building blocks that make up all matter
Chemistry
The science of structure and interactions of matter
Chemical symbol
Designates each element. Uses one or two letters of the elements name in English Latin or another language
Major elements
Four elements that constitute about 96% of the bodies mass: Oxygen, carbon, hydrogen, and nitrogen
How many chemical elements are normally present in the human body?
26
Lesser elements
Contribute about 3.6% to the bodies mass: Calcium, phosphorus, potassium, sulfur,sodium,chlorine, magnesium,and iron.
Trace elements
additional 14 elements that altogether Account for the remaining .4% of the body’s mass.
Oxygen
Major element
O
About 65% of body mass
Part of water and many organic molecules used to generate ATP, a molecule used by cells to temporarily store chemical energy
Carbon
C
Major element
About 18.5% of total body mass
Forms backbone chains and rings of all organic molecules; Carbohydrates, lipids, proteins and nucleic acids (DNA and RNA)
Hydrogen
H
Major element
9.5% Of total body mass
Constituent Of water and most organic molecules; ionized form (H+) Makes body fluids more acidic
Nitrogen
N
Major element
3.2% Of total body mass
Components of all proteins and nucleic acids
What are the major elements?
Oxygen
carbon
hydrogen
nitrogen
Calcium
Ca
Lesser element
About 1.5% Of total body mass
Contributes to hardness of bones and teeth; ionized form (Ca2+) Needed for blood clotting, release of some hormones, contraction of muscles and many other processes
Phosphorus
P
Lesser element
1% of total body mass
Component of nucleic acids and ATP; Required for normal bone and tooth structure.
Potassium
K
Lesser element
.35% of total body mass
Ionized form (K+) Is the most plentiful cation (Positively charged particle) in intracellular fluid; Needed to generate action potentials
Sulfur
S
Lesser element
.25% of total body mass
Component of some vitamins and many proteins
Sodium
Na
Lesser element
.2% of total body mass
Ionized form (Na+) is the most plentiful cation in extracellular fluid; Essential for maintaining water balance; needed to generate action potentials.
Chlorine
Cl
Lesser element
.2% of total body mass
Ionized form (Cl-) Is the most plentiful anion in extracellular fluid; Essential for maintaining water balance
Magnesium
Mg
Lesser element
.1% of total body mass
Ionized form (Mg2+) Needed for action of many enzymes, molecules that increase the rate of chemical reactions organisms
Iron
Fe
Lesser element
.005% of total body mass
Ionized forms (Fe2+ and Fe3+) Are part of hemoglobin
Trace elements
Lesser elements that make up about .04% of total body mass
Aluminum, boron, chromium, cobalt, copper, fluorine, iodine, Manganese, molybdenum, Selenium, silicon, tin, vanadium, and zinc
Hemoglobin
Oxygen-carrying protein in red blood cells
Cation
Positively charged particle
Anion
Negatively charged particle
Atoms
The smallest units of matter that retain the properties and characteristics of the element
Subatomic particles
Compose individual atoms
Nucleus
The dense central core of an atom
Protons
(p+)
A stable positively charged subatomic particle Within the nucleus of an atom
Neutron
(n0)
Electrically neutral subatomic particle within the nucleus of an atom
Electron
(e-)
Negatively charged subatomic particle That move about in a large space surrounding the nucleus of an atom
Electron shells
A grouping of electrons surrounding the nucleus of an atom
Atomic number
The number of protons in the nucleus of an atom
Mass number of an atom
The sum of its protons and neutrons
Isotopes
Atoms of an element that have different numbers of neutrons and therefore different mass numbers
Pg 31
Radioactive isotopes
Are unstable; There nuclei Decay into a stable configuration
Half life of an isotope
Is the time required for half of the radioactive atoms in a sample to decay into a more stable form
Dalton
The standard unit for measuring the mass of atoms and their sub atomic particles
Atomic mass also called atomic weight
The average mass of all naturally occurring isotopes of an element
Ion
And 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 contains Adams of two or more different elements
Free radical
An atom or group of atoms with an unpaired electron in the outermost shell
Antioxidants
Substances that in activate oxygen derived free radicals. Thought to slow the pace of damage caused by free radicals
Chemical bonds
The forces that hold together the atom of a molecule or a compound
Valence shell
The outermost layer of an atom. Contains electrons.
Octet rule
Under the right conditions to a more Adams can interact in ways that produce a chemically stable arrangement of eight valence electrons for each atom
Ionic bond
The force of attraction that holds together ions with opposite charges
Cation
Positively charged ion
Anion
Negatively charged ion
Electrolyte
An ionic compound that breaks apart into positive and negative ions in solution
Covalent bond
When two or more atoms share electrons rather than gaining or losing them
True or false covalent bonds may form between atoms of the same element or between atoms of different elements?
True
Single covalent bond
When two atoms share one electron pair
Double covalent bond
Results when two atoms share two pairs of electrons
Triple covalent bond
When two atoms share three pairs of electrons
Nonpolar covalent bond
In some covalent bonds two atoms share the electrons equally one atom does not attract the shared electrons more strongly than the other atom
Polar covalent bond
The sharing of electrons between two atoms is unequal the nucleus of one atom attracts the shared electrons more strongly than the nucleus of the other atom
Electronegativity
An atoms power to attract electrons to itself
Hydrogen bond
Forms when a hydrogen atom with a partial positive charge attracts the partial negative charge of neighboring electronegative atoms. Most often larger oxygen or nitrogen atoms.
Surface tension
A measure of the difficulty of stretching or breaking the surface of liquid.
Chemical reaction
Occurs when new bonds form or old bonds break between atoms
Reactants
The starting substance in a chemical reaction
Products
The ending substances in a chemical reaction
Energy
The capacity to do work
Each chemical reaction involves ______ changes.
Energy
Potential energy
Energy stored by matter due to its position
Kinetic energy
The energy associated with matter in motion
Examples of kinetic energy
Energy stored in water behind a dam or a person poised to jump down some steps
Chemical energy
A form of potential energy that is stored in the bonds of compounds and molecules
The law of conservation of energy
Although energy can be neither created nor destroyed it may be converted from one form to another
Example of the law of conservation of energy
Some of the chemical energy in the foods we eat is eventually converted into various forms of kinetic energy such as mechanical energy used to walk and talk.
Exergonic reactions
Release more energy than they absorb.
Endergonic reactions
Absorb more energy than they release.
Activation energy
The collision energy needed to break the chemical bonds of the reactants
Concentration (As related to chemical reactions)
The more particles of matter present in a confined space the greater the chance that they will collide
Temperature (as related to chemical reactions)
As the temperature rises particles of matter move about more rapidly. This the higher the temperature of matter the more forcefully particles will collide and the greater the chance of collision will produce a reaction.
Catalyst
Chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur.
Raising the temperature and the number of reacting particles of matter in the body could increase the frequency of collisions and thus increase the rate of chemical reactions but doing so could also damage or kill the body cells. What chemical compounds solve this problem?
Catalysts
Synthesis reactions
When two or more atoms, ions or molecules combine to form new and larger molecules.
Anabolism
All synthesis reactions that occur in the body.
Decomposition reactions
Split up large molecules into smaller atoms, ions, or molecules
Catabolism
The decomposition reactions that occur in your body.
Exchange reactions
Consist of both synthesis and decomposition reactions.
Reversible reaction
The products can revert to the original reactants.
Oxidation
The loss of electrons and in the process the oxidized substance releases energy
Reduction
Refers to the gain of electrons and in the process the reduced substance gains energy.
Oxidation reduction reactions
Are always parallel. When one substance is oxidized another is reduced at the same time.
when a food molecules such as glucose is oxidized the energy produced is used by a cell to carry out its various functions. What is this called?
Oxidation reduction reaction
Inorganic compounds
Usually lack carbon and are structurally simple. Their molecules also have only a few atoms and cannot be used by cells to perform complicated biological functions.
Name some in organic compounds.
Water, many salts, acids and bases.
Organic compounds
Always contain carbon usually contain hydrogen and always have covalent bonds. Most are large molecules and many are made up of long chains of carbon atoms.
What percentage of the human body is made up of organic compounds?
38-43%
What percent of an adult human body is made up of in organic compounds besides water?
1-2%
What percentage of an adult human body is made up of water?
55 to 60%
What is the most important and abundant inorganic compound in all living systems?
Water
Solvent
The substance in a solution that dissolves another substance
Solute
The substance in a solution that is dissolved by another substance
Hydrophilic
Solutes that are charged or contain polar covalent bonds.
Hydrophobic
Molecules that contain mainly nonpolar covalent bonds
Hydrolysis
Decomposition of a compound by reaction with water.
During digestion decomposition reactions breakdown large nutrient molecules into smaller molecules by the addition of water molecules. What kind of reaction is this?
Hydrolysis
Mixture
A combination of elements or compounds that are physically blended together but not bound by chemical bonds.
Solution
?
Colloid
?
Example milk
Suspension
In a solution material that may mix with the liquid or suspending medium for some time but eventually settles out
Concentration
?
Percentage
One common way to express the concentration of a solution which gives the relative mass of the solute found in a given volume of solution
Moles per liter
A way to express concentration of a solution in units which relates to the total number of molecules in a given volume of a solution
Mole
The amount of any substance that has a mass in grams equal to the sum of the atomic masses of all it’s atoms
Disociate
When inorganic, acids, bases or salts dissolved in water they separate into ions and become surrounded by water molecules
Acid
A substance that disassociates into one or more hydrogen ions and one or more anions
Proton donor
Acid
Base
Removes hydrogen ions from a solution and is therefore a proton acceptor
What is another name for a base?
Proton acceptor
Hydroxide ions
?
A salt Does what when dissolved in water?
When dissolved in water dissociates into cations and anions neither of which is hydrogen ions or hydroxide ions
Ph scale
The scale in which a solution’s acidity or alkalinity is expressed
Buffer systems
Function to convert strong acids or bases into weak acids or bases
Even though strong acids and bases are continually taken into and formed by the body, the pH of fluids inside and outside cells remains almost constant. Why?
The buffer system
Buffers
The chemical compounds that can convert strong acids or bases into weak ones.
Carbonic acid-bicarbonate buffer system
Can compensate for either an excess or shortage of hydrogen ions
Hydrocarbon
Carbons that are bonded to hydrogen
Carbon skeleton
The chain of carbon atoms in an organic molecule
Macromolecules
Small organic molecules that combine into very large molecules
Polymers
A large molecule formed by the covalent bonding of an identical or similar small building block molecules called monomers
Monomers
Small building block molecules
Isomers
Molecules that have the same molecular formula but different structures
Carbohydrates
Organic compounds that have several functions. Sugars, glycogen, starches and cellulose. Function mainly as a source of chemical energy for generating ATP needed to drive metabolic reactions
Simple sugars
Monosaccharides and disaccharides.
Monosaccharides
The monomers (Small building blocks of molecules) of carbohydrates
Disaccharide
A molecule formed from the combination of two monosaccharides by dehydration synthesis
Polysaccharides
A major group of carbohydrates. Each polysaccharide molecule contains tens or hundreds of monosaccharides joined to dehydration synthesis
Glycogen
The main polysaccharide in the human body which is made entirely of glucose monomers linked to one another in branching chains.
Starches
Polysaccharides formed from glucose by plants
Cellulose
A Polysaccharide formed from glucose by plants cannot be digested by humans but does provide bulk to eliminate feces
Lipids
Important group of organic compounds. Make up 18 to 25% of body mass in lean adults
Liptoteins
To become more soluble in blood plasma other lipid molecules join with Hydrophilic protein molecules
Types of lipids in the body. Pg 47
Fatty acids. Triglycerides. Phospholipids. Steroids. Eicosanoids.
Fatty acids
Among the simplest lipids which are used to synthesize triglycerides and phospholipids
Saturated fatty acid
Contains only single covalent bonds between carbon atoms of the hydrogen carbon chain.
Unsaturated fatty acid
Contains one or more double covalent bonds between carbon atoms of the hydrocarbon chain
Triglycerides/triacyglycerols
The most plentiful lipids in your body and in your diet
Glycerol
A three carbon molecule that forms the backbone of a triglyceride
Fat
A triglyceride that is a solid at room temperature
Saturated fat
A fat but mainly consists of saturated fatty acids
Oil
A triglyceride that is liquid at room temperature
Monosaturated fats
Contain triglycerides that mostly consist of monounsaturated fats
Olive oil peanut oil canola oil most nuts and avocado
Polyunsaturated fats
Contain triglycerides that mostly consists of polyunsaturated fatty acids. Corn oil safflower oil sunflower oil soybean oil fatty fish
Phospholipids
Have a glycerol Backbone and two fatty acid chains attached the first two carbons
Amphipathic
Molecules that have both polar and nonpolar parts
Steroids
Have four rings of carbon atoms
Sterols
Steroids I that have at least one hydroxyl group (Not 100% sure on this definition)
Eivosanoids
Lipids derived from a 20 carbon fatty acid called arachidonic acid.
Prostaglandins
Modify responses to hormones, contribute to the inflammatory response, prevent stomach ulcers, dilate airways to lungs, regulate body temperature and influence formation of blood clots. One of two principal subclasses of eicosanoids
Leukotrienes
Participate in allergic and inflammatory responses. A subclass of eicosanoids
Proteins
Large molecules that contain carbon, hydrogen, oxygen and nitrogen. Some proteins also contain sulfur. A normal lean adult body is 12 to 18% protein.
Amino acids
Monomers of proteins.
How many different types of amino acids are there?
20
True or false each amino acid has a hydrogen Adam and three important functional groups?
True
What are the three important functional groups attached to a central Carbon atom of an amino acid?
An amino group, and acidic carboxyl group, and a side chain
Peptide bond
The covalent bond joining each pair of amino acids
Structural protein
Form structural framework of various parts of the body
Example collagen in bone and other connective tissue
Regulatory protein
Function as hormones that regulate various physiological processes; control growth and development; as neurotransmitters, mediate responses of nervous system
Example insulin
Contractile
Allow shortening of muscle cells which produces movement.
Examples myosin and actin
Immunological protein
Aid responses that protect body against foreign substance and invading pathogens.
Examples antibodies, interleukins
Transport proteins
Carry vital substances throughout the body.
Example hemoglobin transports most oxygen and some carbon dioxide in the blood.
Catalytic protein
Act as enzymes that regulate biochemical reactions.
Example salivary amylase, sucrase, ATPase
Dipeptide
The combination of two amino acids
Tripeptide
The combination of three amino acids
Peptide
4 to 9 amino acids
Polypeptide
10 to 2000 or more amino acids
Primary structure
The unique sequence of amino acids that are linked by covalent peptide bonds to form a polypeptide chain
Sickle cell disease
When a nonpolar amino acid replaces a polar amino acid through two mutations in the oxygen-carrying protein hemoglobin. This change amino acids diminishes hemoglobins water solubility. As a result the altered hemoglobin tends to form crystals inside the red blood cells producing deformed sickle shaped cells that cannot properly squeeze through narrow blood vessels
How many levels of structural organization do proteins have?
Four
What are the four levels of structural organization in protein?
Primary structure, secondary structure, tertiary structure, quaternary structure.
Secondary structure of proteins
The repeated twisting or folding of neighboring amino acids in the polypeptide chain.
What are the two common secondary structures of protein?
Alpha helixes and beta-pleated sheets
Tertiary Structure of protein
Three-dimensional shape of the polypeptide chain.
True or false each protein has the same tertiary structure determines how it will function.
False each protein has a unique tertiary structure
Quaternary structure of protein
In those proteins that contain more than one polypeptide chain the arrangement of the individual polypeptide chains relative to one another.
Fibrous proteins
In soluble in water and their polypeptide chains formed long strands are parallel to each other
What are some structural Functions of fibrous proteins?
Collagen (strengthens bones, ligaments and tendons)
Elastin - provides stretch and skin, blood vessels, and lung tissue
Keratin - Forms structure of hair and nails and waterproofs the skin
More on page 54
Globular proteins
Are more or Less soluble in water and their polypeptide chains and are spherical in shape
Denaturation
When a protein encounters an altered environment and unravels and loses its characteristic shape
Enzymes
In living cells most catalysts are protein molecules
Apoenzyme
In some enzymes; the protein portion
Cofactor
Nonprotein portion of an enzyme
Substrate
The specific reactant molecules on which the enzyme acts
Active site
In some cases the part of the enzyme that catalyzes the reaction
Enzyme substrate complex
The subtrates make contact with the active site on the surface of the enzyme molecule, forming a temporary intermediate compound
Nucleic acid
Huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen and phosphorus
DNA - deoxyribonucleic acid
Forms the inherit genetic material inside each human cell
Gene
A segment of a DNA molecule
Ribonucleic acid - RNA
The second type of nucleic acid that relays instructions from the genes to guide each cells synthesis of proteins from amino acids
Nucleotides
The repeating chain of monomers that build nucleic acid.
Nitrogenous bases
Adenine, thymine, cytosine, and guanine.
Adenine and guanine Are larger double ring bases called
Purines
Pyrimidines
Smaller single ring bases; thymine and cytosine
Each nucleotide of DNA consists of what three parts?
Nitrogenous base, pentose sugar, phosphate group
Pentode sugar
A five carbon sugar called deoxyribose attaches to each Base in DNA
Double helix
A spiral ladder model of DNA
Ribose
The sugar in the RNA nucleotide
DNA fingerprinting
A technique used in the research and in courts of law to ascertain whether a person’s DNA matches the DNA obtained from samples or pieces of legal evidence such as blood stains or hairs
Adenosine triphosphate - ATP
The energy currency of living systems
Adenosine diphosphate - ADP
A molecule that results from the removal of the third phosphate group in ATP
