Chapter 2 And 4 - Carbon And The Chemical Context Of Life Flashcards
Matter
Anything that takes up space and has mass
Element
A substance that cannot be broken down to other substances by chemical reactions
Compound
A substance consisting of two or more elements combined in a fixed ratio in
Essential Elements
An element that an organism needs to live a healthy life and reproduce
Trace elements
Elements required by elements in only minute qualities
Atom
The smallest unit of matter that still retains the properties of an element
Atomic Nucleus
Where protons and neutrons are packed at the centre of an atom. Protons give the nucleus a positive charge
Electrons around nucleus
The rapidly moving electrons form a “cloud” of negative charge around the nucleus, and it is the attraction between opposite charges that keeps the nucleus electrons in the vicinity of the nucleus
Atomic Number
Number of protons
Mass number
Sum of neutrons and protons in the nucleus of an atom
Isotopes
Different atomic forms of the same element
Radioactive isotope
An isotope whose nucleus decays spontaneously, giving off particles and energy
Energy
That capacity to cause change by doing work
Potential energy
The energy that matter processes because of its location or structure
Valence Electron
Electrons in the outermost shell
Chemical Bonds
Attractions that hold atoms together
Covalent Bonds
The sharing of a pair of valence electrons by two atoms
Molecule
Two or more atoms held together by covalent bonds
Single Bond
Shares one valence electron
Double bond
Share two pairs of valence electrons
Valence
An atoms bonding capacity
Electronegativity
The attraction of a particular atom for the electrons of a covalent bond
Nonpolar covalent bond
In a covalent bond, between two atoms of the same element, the electrons are shared equally because the two atoms have the same electronegativity
Polar covalent bond
When an atom is bonded to a more electronegative atom, the electrons of the bond are not shared equally
Electronegativity Scale
O>N>C~H
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Ions
Two oppositely charged atoms (or molecules)
Positive = Cation Negative = Anion
Ionic Bond
Unpaired valence electrons are transferred from one atom to another
Hydrogen Bond
Hydrogen bound to an atom that strongly attracts the shared electrons (that is more electronegative)
Van Der Waals Interactions
Because they move around the nuclei, electrons are not distributed evenly in atoms or molecules
Functional Groups
See textbook!
Hydroxyl Group
Is polar due to electronegative oxygen. Forms hydrogen bonds with water, helping dissolve compounds such as sugars
Compound name: Alcohol
Carbonyl Group
Sugars with ketone groups are called ketoses; those with aldehydes are called aldoses.
Compound name: ketone or aldehyde
Carboxyl Group
Acts as an acid (can donate H+) because the covalent bond between oxygen and hydrogen is so polar
Compound Name: carboxylic acid or organic acid
Amino Group
Acts as a base; can pick up an H+ from the surrounding solution (water, in living organisms)
Compound name: Amine
Phosphate Group
Contributes negative charge (1- when positioned inside a chain of phosphates; 2- when at the end). When attached, confers on a molecule the ability to react with with water, releasing energy
Compound Group: organic phosphate
Methyl Group
Affects the expression of genes when on DNA or on proteins bound to DNA. Affects the shape and function of male and female sex hormones.
Compound name: methylated compound
Carbon Bonds
Carbon can complete valence shells by sharing electrons with 4 other atoms
Organic Chemistry
The study of compounds containing carbon
Hydrocarbons
Organic molecules consisting of only carbon and hydrogen
Isomers
Compounds that have the same number of atoms of the same elements but different structures hence different properties
Cis-Trans Isomers
(Formerly called geometric isomers) when carbons have covalent Bonds to the same atoms, but these atoms differ in their spatial arrangements due to the inflexibility of double Bonds.
Enantiomers
Isomers that are mirror images of each other and that differ in the shape due to the presence of an asymmetrical carbon, one that is attached to four different atoms or groups of atoms
Adenosine Triphosphate (ATP)
Consists of an organic molecule called adenosine attached to a sting of 3 phosphate groups
