Chapter 2 : Chemical Basis of Life Flashcards
Matter
Anything that has weight and takes up space
Solid, Liquid, Gas, Plasma
Mass
Measure of the amount of matter (grams)
Weight
Measure of the pull of gravity on the mass of an object
Elements
The smallest form of matter (must maintain unique characteristics
A single element is considered
An atom
Atoms of the different elements vary in
Size and how they interact with one another
An atom consists
of a nucleus containing protons, neutrons, and electrons that orbit around the nucleus
A proton’s charge
Positive
A neutron’s charge
None / Neutral
An electron’s charge
Negative
Elements are arranged on what and according to what?
On the periodic table
According to their atomic number
The atomic number
The number of protons located in the nucleus of a particular atom
How can you tell the number of electrons from the neutral
A single atom of an element has a neutral charge, the atomic number can also tell us the number of electrons present in the orbitals or shells of the atoms
The number of electrons will determine what?
How the element interacts of forms bonds with other elements
Mass number
The number of protons and neutrons in an atom
The number of neutrons of an element varying causes
Isotopes
Atomic Weight
The average mass of all the isotopes of a certain type
Atoms want what in their outer most shell to become stable and happy :D
The maximum number of electrons
What do atoms do to stay/become stable
They form bonds by gaining, losing, or sharing electrons with other bonds
Ionic bonds
When atoms can obtain a stable number of electrons by giving up or gaining forming compounds
What forms when ionic bonds separate
Charged atoms called ions are formed
Covalent bonds form when
2 or more elements share electrons to become stable
Molecule
Stable compound formed by covalent bonding
Ionic vs. Covalent
Ionic bonds form between elements on opposite sides of the Periodic table
Covalent bonds form between elements on the same side of the Periodic Chart or between 2 atoms of the same element
Electron Dot Diagram
Uses dots to represent the filing of shells and th exchange or sharing of electrons
Polarity
One side of a molecule having a slight charge ans ones side having a slight negative charge
What causes polarity
Unequal sharing of electrons
Hydrogen bonds
Bonds between polar molecules caused by Hydrogen slight positive charge
Cohesion
Attraction between like substances
EX: Surface tension - water molecules stick together
Adhesion
Attraction between unlike substances
EX: “sweat” on a glass
Capillary Action
Combination of cohesion and adhesion
EX: liquid in a straw
pH
The measure of acidity or alkalinity of a substance by measuring the amount of H+ ions present
pH scale
Lists on order of acid to base in relation to neutral
7 on the pH scale is
Neutral
Closer to 14 on the pH scale
The stronger the base
Closer to 0 on the pH scale
The stronger the acid
Bases will neutralize
Acids and vise versa
The pH of a solution greatly affects what
What physical reactions can take place within the solution
Characteristics of acids
Taste sour, burn skin
Characteristics of bases
Taste bitter, feel slippery
Organic Molecules
- Usually associated with living things
- Always contain Carbon and Hydrogen
- “large” macromolecules made from 1,000’s of atoms
- Always have Covalent Bonds
4 main categories of “organic” molecules that make up our bodies
- Proteins
- Carbohydrates
- Lipids
- Nucleic Acids
Proteins
Molecules composed of amino acids
Types of proteins
- Structural proteins
- Enzymes
- Receptor
- Antibodies
- Hormones
Structural Proteins (of the body)
Construct or organs (hair, skin, muscles, stomach)
Enzymes
Speed up chemical reactions
Receptors
Recognize other cells
Antibodies
Recognize and destroy foreign materials in the body
Hormones
Chemical messengers of the endocrine system
Carbohydrates
Molecules of carbon, hydrogen, and oxygen that provide quick energy for our cells
The 3 types of Carbohydrates
- Monosaccharide
- Disaccharide
- Polysaccharide
Monosaccharide
Single sugar
- Glucose - cellular fuel
- Fructose - fruit sugar
- Galatose - milk sugar
Disaccharide
Double sugar
-Sucrose - table sugar = glucose + fructose
Polysaccharide
Three or more sugars
- Glycogen - 100’s of sugars stored in liver of animals
- Starch - 100’s of sugars stored in cells of plants
Lipids
- Non-polar, C-H-O molecules that are insoluble in water
- Store large amounts of energy in the bonds between atoms
- Composed of 1 Glycerol molecule (back bone) and 3 Fatty Acids (tails)
3 Types of Lipids
- Triglycerides
- Phospholipids
- Steroids
Triglycerides
Fats and oils that provide large amounts of energy in their bonds
Phospholipids
Make cell membranes
Steroids
Complex lipids varied functions such as cholesterol, adrenaline, estrogen, ect
Nucleic Acids
Molecules of DNA and RNA that encode our genetic information
Nucleic Acids are composed of
Nucleotides
Nucleotides
- 5 Carbon sugar (ribose or deoxyribose)
- Phosphate group
- Nitrogen bases : Adenine, Guanine, Cytosine, and Thymine ( or Uracil in RNA)
This makes the outer “ladder” of the Double Helix
The 5 carbon sugar alternating with the phosphate group
The nitrogen bases form the
“Rungs” of the ladder (of the double helix)
Bases are always paired to a
Specific partner
Adenine to
Thymine
Guanine to
Cytosine
Each sequence of 3 base pairs encodes for
Amino acids (triple codon sequence)
Chromosome
2 identical strands of DNA that encode for the same traits (eye color, hair color, height)
