Chapter 2 Flashcards
What is an element
The simplest type of matter composed of atoms of only one kind
What is an atom
Smallest particle of an element that has characteristics of that element
What are the biologically significant elements? (CHONPS)
-carbon
-hydrogen
-oxygen
-nitrogen
-phosphorus
-sulfur
What is the charge, mass, and location of a proton
Positive charge, 1 atomic mass unit, in the central nucleus
What is the charge, mass, and location of a neutron
No charge, 1amu, in the central nucleus
What is the charge, mass, and location of an electron
Negative charge, 0 amu, in electron shell
What is the atomic number
Number of protons an atom has
What is mass number
Number of protons plus neutrons
How to figure out number of neutrons in an element on the periodic table
Atomic mass - atomic number (protons) = neutrons
If an element has an atomic number of 7, how many electrons does it have?
7 (protons=electrons)
What are isotopes?
Two or more forms of same element with same number of protons and electrons but different neutron number
Do isotopes of an element have the same atomic mass?
No, they have different atomic masses
What are radioactive isotopes?
Unstable isotopes that give off radiation
What are some uses of radioactive isotopes?
-tracking hormone uptake
-treating cancer (radiation therapy)
-medical imaging
-sterilization of materials to be used in surgery
What is an ion
-charged atoms with unequal numbers of electrons and protons
-an atom that gains or loses electrons to become stable
What charge is a cation and when is it formed?
Net positive charge, formed when an atom loses electrons
What is the charge of an anion and when is it formed?
Net negative charge, formed when an atom gains electrons
What are electrolytes?
Salts that ionize in water and form solutions capable of conducting an electrical current
Why are electrolytes important?
-chemical reactivity
-osmotic effects (influence water movement)
-electrical effects on nerve and muscle tissue
What can electrolyte imbalances cause?
Muscle cramps, brittle bones, cardiac arrest, coma, death
Electrolyte- Calcium chloride (CaCl2)
Cation and anion
Cation- Ca2+
Anion- 2 Cl-
Electrolyte- Disodium phosphate (Na2HPO4)
Cation- anion
Cation- 2 Na+
Anion- HPO4 ^2-
Electrolyte- Magnesium chloride (MgCl2)
Cation-anion
Cation- Mg^2+
Anion- 2 Cl-
Electrolyte- potassium chloride (KCl)
Cation- anion
Cation- K+
Anion- Cl-
Electrolyte- sodium bicarbonate (NaHCO3)
Cation-anion
Cation- Na+
Anion- HCO3-
Electrolyte- sodium chloride (NaCl)
Cation-anion
Cation- Na+
Anion- Cl-
What is a molecule
A substance composed of two or more atoms united by a chemical bond (example: hydrogen (H2))
What is a compound
A substance composed of two or more different types of atoms chemically combined (Ex. Water- H2O)
What are inorganic molecules
Substances that do not contain C-H bonds
-water
-oxygen
-carbon dioxide
What are organic molecules
Substances that contain C-H bonds
-carbohydrates
-proteins
-lipids
-nucleic acids
What are the three kinds of chemical bonds?
-covalent bonds
-ionic bonds
-hydrogen bonds
What is an ionic bond
A complete transfer of electrons between two atoms. Results in separate positively charged and negatively charged ions
Covalent bond
-one or more pairs of electrons are shared between atoms
-strongest type of chemical bond
Polar covalent bond
Electrons are not shared equally (results in a slight positive charge on one side and a slight negative charge on the other side of a molecule)
Nonpolar covalent bond
Electrons are shared equally (results in an even charge in a molecule)
Hydrogen bonds
The attraction of oppositely
charged ends of one molecule to another molecule (no new molecules are formed)
Hydrophilic
Substances that dissolve in water (water-loving)
Hydrophobic
Substances that do not dissolve in water (water-fearing)
Adhesion
attraction between different substances
-tendency of one substance to cling to another
-attraction of water molecules to other polar molecules
Cohesion
attraction between similar substances
-tendency of like molecules to cling to each other
-attraction of water molecules to other water molecules
Acid
Any substance that increases hydrogen ion concentration
Base
Any substance that decreases hydrogen ion concentration
Buffer
A solution of an acid-base pair in which acid and base components occur in similar concentrations
pH scale
Neutral= pH of 7
Acidic= pH less than 7
Alkaline or basic= pH greater than 7
What does our body use to prevent changes in pH
Buffers
What can pH disturbances lead to
-disrupt physiological functions and alter drug actions
-can lead to tremors, paralysis, or even death
What are reactants in a chemical reaction
Substances that enter into a chemical reaction
What are products in a chemical reaction
Substances that result from the reaction
Metabolism
The sum of all of the anabolic and catabolic chemical reactions in the body
When chemical bonds are made it is called what
Synthesis reactions (anabolism)
When chemical bonds are broken it is called what
Decomposition reactions (catabolism)
Hydrolysis
Water is used to break a chemical bond (water is a reactant in the reaction)
Dehydration synthesis
Anabolic reaction where water is a product
Reaction rates are affected by what
-concentration (more concentrated=more collisions)
-temperature (higher temp=greater collision force, faster rate)
-catalysts or enzymes (speeds up reactions)
Carbohydrates examples and function
-divided into monosaccharides, disaccharides, and polysaccharides
-EXAMPLE: glucose (blood sugar)
-energy sources and structure
Lipids examples and functions
-Examples: anabolic steroids, fat
-Functions: protection, insulation, component of cell membranes, energy source
Proteins examples and function
-Example: insulin, amino acids
-Function: regulate processes, aid transport, protection, muscle contraction, structure, energy
Nucleic acids examples and function
-Example: DNA and RNA
-Function: store genetic info, involved in protein synthesis
Carbohydrates: monosaccharides
-simple sugars
-glucose, fructose, and galactose are important in the diet as energy sources
-ribose and deoxyribose are components of ATP, DNA, and RNA
Disaccharides
Two simple sugars bound together by dehydration synthesis
Examples: lactose, sucrose, maltose
Three polysaccharides and their uses
1.Glycogen- energy storage in animals (made by cells of liver, muscles, brain, uterus, and vagina)
2.Starch- energy storage in plants
3.Cellulose- structural molecule of plant cell walls (fiber in our diet)
Lipids: Fats functions
Protection, insulation, energy source
Saturated fatty acids
Contains all single bonds in the carbon chain, which produces a more rigid structure
Unsaturated fatty acids
Contains one or more double bonds in the carbon chain, which produces a more relaxed structure (better because they do not stick to the inside of blood vessels)
Cholesterol (steroid)
The parent steroid from which the other steroids are synthesized
Examples of cholesterol, synthesized, and function
-Examples: cortisol, progesterone, estrogens, testosterone
-synthesized only by animals, especially in liver cells
-functions: physiological regulators and component of cell membranes
Protein function
-structural support
-catalysts (enzymes)
-hormones
-transport
-building block
Enzymes
Most are proteins, reduces activation energy needed for a reaction
Factors that alter enzymes
-heat
-changes in pH
-radiation
-electricity
-chemicals
DNA
Genetic material of cells copied from one generation to next
What is DNA composed of
Two strands of nucleotides held together by hydrogen bonds
Adenine-Thymine
Guanine-Cytosine
What is the sugar in DNA
Deoxyribose
What is the sugar in RNA
Ribose
RNA composition and use
Adenine-Uracil
Guanine-Cytosine
Involved in protein synthesis
RNA - sugar, base, and strand
-sugar=ribose
-Base= A,G,C,U
-single- stranded
DNA - sugar, base, and strand
-sugar=deoxyribose
-base= A,G,C,T
-double-stranded
What is ATP
Adenosine triphosphate. The main energy currency of the cell
