Chapter 2 Flashcards
Matter
Anything that occupies space and has mass
Mass
Amount of matter in any object, which does not change
Weight
The force of gravity acting on matter, does not change
What are the major elements?
- Oxygen
- Carbon
- Hydrogen
- Nitrogen
What are the eight lesser elements?
Calcium
Phosphorus
Potassium
Sulfur
Sodium
Chlorine
Magnesium
Iron
What are elements made up of?
Atoms
Oxygen
65% of body mass, part of water and many organic molecules. Used to generate ATP. Used by cells to temporarily store chemical energy
Carbon
18.5% of body mass, forms backbone chains and rings of all organic molecules: carbohydrates, lipids, proteins, nucleic acids (DNA and RNA)
Hydrogen
9.5% of body mass, constituent of water and most organic molecules; ionized from H+ makes body fluids more acidic
Nitrogen
3.2% of body mass, component of all proteins and nucleic acid
Calcium
1.5% of body mass, contributes to hardness of bones and teeth; ionized from Ca2+ needed for blood clotting, release of some hormones, contraction of muscle, and many other processes
Phosphorus
1.0% of body mass, component of nucleic acids and ATP; required for normal bone and tooth structure
Potassium
.35% of body mass, ionized from K+ is the most plentiful cation (positively charged particle) in intercellular fluid; needed to generate action potentials
Atomic number
Number of protons in the nucleus of an atom
Mass number
Sum of an atoms protons and neutrons
Isotopes
Atoms of an element that have different numbers of neutrons and therefore different mass numbers
Radioactive isotopes
Unstable, nuclei decay into a stable configuration emitting radiation
Compound
A substance that contains atoms of two or more different elements
Ion
An atom that gives up or gains electrons
Molecule
When two or more atoms share electrons, molecules can consist of two atoms of the same kind
Chemical bonds
Forces that hold together the atoms of a molecule or a compound
Ionic bond
The force of attraction that holds together ions with opposite charges
Cation
Positively charged ion
Anion
Negatively charged ion
Electrolyte
Ionic compound that breaks apart into positive and negative ions in solution
Covalent bonds
Forms when two or more atoms share electrons rather than gaining or losing them
If two atoms share a large amount of electron their covalent bond will be?
Stronger
Single covalent bond
Atoms share one electron pair
What’s an example of an important polar covalent bond?
The bond between oxygen and hydrogen in a water molecule
Polar covalent bond
Sharing of electrons is unequal, resulting molecule has a partial negative charge which attracts electrons more strongly which is called electronegativity
Hydrogen bond
Forms when a hydrogen atom with a partial positive charge attracts the partial negative charge of a neighbouring electronegative atoms, usually larger oxygen or nitrogen atoms
Energy
Capacity to do work
Chemical energy
A form of potential energy that is stored in the bonds of compounds and molecules
What’s the principle known as law of conservation of energy
Energy can be neither created nor destroyed, it may be converted from one form to another
What happens when energy goes from one form to another?
Releases heat, some of which is used to maintain normal body temp
Exergonic reactions
Release more energy than they absorb
Endergonic reactions
Absorb more energy than they release
Metabolism
Refers to the chemical reactions in the body
Activation energy
Collision energy needed to break the chemical bonds of the reactants
What influences the chance that a collision will occur and cause a chemical reaction?
Concentration
Temperature
Concentration
The more particles of matter present in a confined space, the greater the chance that they will collide
Temperature
Temperature rises, particle of matter move about more rapidly
Catalyst
Chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur
Types of chemical reactions
Synthesis reactions- anabolism
Decomposition reactions- catabolism
Reversible reactions
Oxidation-reduction reactions
Exchange reactions
Anabolic reactions
Usually endergonic because they absorb more energy than they release
Decomposition reactions
Split up large molecules into smaller atoms, ions, or molecules and are referred to as catabolism
Exchange reactions
Use synthesis and decomposition reactions
Oxidation
Refers to loss of electrons
Reduction
Refers to the gain of electrons
Oxidation-reduction reactions
One substance gains molecules and one loses molecules at the same time
Inorganic compounds
Lack carbon and are structurally simple
Organic compounds
Contain carbon, usually contain hydrogen and always have covalent bonds
Water
Most important and abundant inorganic compound in all living systems
What does it mean when you say waters heat of vaporization is high?
You need large amounts of heat to change it from a liquid to a gas
mixture
Combination of elements or compounds that are physically blended together but not bound by chemical bonds
Colloid
Particles are large enough to scatter light
Suspension
Material may mix but eventually settles out
What does it mean that water can release or absorb a relatively large amount of heat with only a modest change in temperature?
It has a high heat capacity
When inorganic acids, bases, or salts dissolve in water, they what?
Dissociate
What does an acid dissociate into?
One or more hydrogen ions H+
Dissociate
When inorganic acids, based, or salts dissolve in water, they separate into ions and become surrounded by water molecules
What is an acid?
A substance that dissociates into one or more hydrogen ions and one or more anions
What is a base?
Removes hydrogen ions from a solution
Buffer system
Works to convert strong acids or bases into weak acids or bas s
Carbonic acid-bicarbonate buffer system
Carbonic acid can act as a weak acid, and bicarbonate ion can act as a weak base. So this buffer system can compensate for either an excess or shortage of hydrogen ions
Small organic molecules that can combine into very large molecules?
Macromolecules
Large molecule formed by the covalent bonding of many identical or similar small building-block molecules called monomers?
Polymers
Molecules that have the same molecular formula but different structures are called?
Isomers
What do carbohydrates include?
Sugars, glycogen, starches, cellulose
Major groups of carbohydrates
Monosaccharides
Disaccharide
Polysaccharide
Monosaccharide
Simple sugar, 3-7 carbon atoms
Disaccharide
Simple sugar, formed by two monosaccharides through dehydration synthesis
Polysaccharide
Tens or hundreds monosaccharides joined through dehydration synthesis, water insoluble, not sweet. Main one glycogen. Starches, cellulose.
Different types of lipids?
Fatty acids
Triglycerides
Phospholipids
Steroids
Eicosanoids
Prostaglandins
Leukotrienes
Lipids
Organic compound, 18-25% of body mass, contain carbon, hydrogen, and oxygen. Insoluble in water
Fatty acids
Used to synthesize triglycerides and phospholipids. Can be catabolism’s into ATP
Saturated fatty acid
One single covalent bond between the carbon atoms of the hydrocarbon chain. Because they lack double bonds each carbon atom of the hydrocarbon chain is saturated with hydrogen atoms.
Unsaturated fatty acid
Contains one or more double covalent bonds between the carbon atoms of the hydrocarbon chains. Not completely saturated with hydrogen atoms
Triglycerides
Body’s most highly concentrated form of chemical energy
Glycerol
Saturated fat
Mono saturated fat
Polyunsaturated fat
Proteins
Large molecules that contain carbon, hydrogen, oxygen and nitrogen
Monomers of proteins are amino acids
Structural
Regulatory
Contractile
Immunological
Transport
Catalytic
Peptide bond
Covalent bond joining each pair of amino acids
Properties of enzymes?
Highly specific-binds only to particular substrate
Very efficient
Enzymes are subject to a variety of cellular controls
How does an enzyme work?
- Substrates make contact with active site on surface, forming enzyme-substrate complex
- Substrate molecules transformed by the rearrangement of existing atoms, break down substrate molecule or combine several substrate molecules into the products of the reaction
- After the reaction is completed the reaction products move away from the enzyme, the unchanged enzyme is free to attach to other substrate molecules
Nucleic acids
DNA and RNA
Different parts of the nucleotide?
- Nitrogenous base
- Pentode sugar
- Phosphate group
Removing the third phosphate group in ATP produces what?
A molecule called adenosine diphosphate (ADP)
Where does the cell get the energy required to produce ATP?
Supplied mainly by the catabolism of glucose in a process called cellular respiration
Two phases of cellular respiration?
Anaerobic phase
Aerobic phase
