Chemical Level of Organization Flashcards
Fundamental unit in chemistry
CHEMICAL ELEMENTS
how many elements total
112
how many elements present in human body?
26
what 4 major elements make up 96%
(O, C, H, and N)
Smallest unit of an element that retains characteristics of an element
atoms
Atom contains:
- Nucleus that has protons (+), neutrons (0)
* Electrons (–) surrounding nucleus
atom’s total charge
neutral
Protons # = electron #
how to get atomic number?
=number of protons= number of electrons
how to get mass number?
number of protons + number of neutrons
What happens when an atom gives up or gains an electron?
ion
What happens when atoms share electrons?
molecule
What happens when two or more different atoms held together with chemical bonds ?
compound
IONS, MOLECULES AND COMPOUNDS are described by?
molecular formula
In molecular formula, what does subscript indicate?
of atoms of element
Attraction between atoms to form attachments
CHEMICAL BONDING
What determines type of chemical bonding
?
of electrons in outer shell
types of chemical bonds
ionic
covalent
hydrogen
what bond happens when electron is donated or accepted from another atom?
IONIC BONDS
Ionic bonds typically occur between atoms in which:
- One has just 1 or 2 electrons in outer shells
* Other has almost full outer shell (6 or 7 electrons)
• If electron is accepted, atom →
anion (-)
negative ion is..
anion
If electron is donated, atom →
cation (+)
positive ion is…
cation
what bonding happens when:
Opposite charges attract →
ionic bonding
Sharing of electrons in outer shell →
covalent bonds
Covalent bond typically occurs between atoms in which:
-outer shells are about
half full.
Form when a hydrogen atom (with a partial positive charge)
attracts the partial negative charge of neighboring atoms,
such as oxygen or nitrogen.
HYDROGEN BONDS
Contribute strength and stability within large complex
molecules
HYDROGEN BONDS
Occur when old bonds break and new bonds form
CHEMICAL REACTIONS
types of chemical reactions
synthesis
decomposition
exchange
reversible
putting atoms together to form larger molecules
synthesis
A + B → AB
SYNTHESIS
Synthesis in the body
anabolism
• Splitting molecules apart
decomposition
AB → A + B
DECOMPOSITION
Decomposition in the body
catabolism
Involve both synthesis and decomposition
EXCHANGE
AB + CD → AD + BC
EXCHANGE
Can go in either direction: synthesis or decomposition or
exchange
REVERSIBLE
CLASSES OF CHEMICALS
inorganic
organic
Structure: lack C-H bonds; structurally simple
Inorganic
what kind of chemical?
Water, carbon dioxide, bicarbonate, acids, bases, and salts
inorganic
Structure:
• All contain C-H bonds
• Structurally complex (include polymers composed of many units =
monomers)
Organic
A + B ↔ AB
REVERSIBLE
AB + CD ↔ AD + BC
REVERSIBLE
carbohydrates, lipids, proteins, nucleic acids are under what class of chemical?
Organic
Characteristics of water
• Most abundant chemical in human body
• Good solvent and lubricant
• Takes part in chemical reactions
• Absorbs and releases heat slowly; regulates body
temperature
• Involved in digestion, circulation, and elimination of
wastes
always have covalent bond
Organic
___dissolves → H+ (1 or more)
Acid
____ dissolves → OH-
1 or more
Base
Acid dissolves →
H+ (1 or more)
• Base dissolves →
OH-
1 or more
Acid + base →
salt
The concentration of H+ or OH– expressed on the pH scale
PH CONCEPT
pH scale:
0–14
pH 7.0:
H+ concentration = OH–
concentration
(neutral)
pH < 7.0
more H+ (acid)
pH > 7.0
more OH–
alkaline
Most common sources of energy for humans
CARBOHYDRATES
Three major classes of ccarbohydrates
mono-, di-, poly-
simple sugar
Monosaccharide
two bonded monosaccharides
Disaccharides
Larger carbohydrates formed by dehydration synthesis and
broken down by _________
hydrolysis
Glucose + fructose ↔
sucrose (table sugar)
Glucose + galactose ↔
lactose (milk sugar)
Glucose + glucose↔
maltose
Monosaccharides (monomers) in long chains
• Complex branching structures not usually soluble in
water
• Glycogen: carbohydrate stored in animals (liver, muscles)
• Starch: carbohydrate stored in plants (potatoes, rice, grains)
• Cellulose: plant polymer (indigestible fibers)
POLYSACCHARIDES
usually uses -ose
monosaccharides
glycogen, starch, cellulose
POLYSACCHARIDES
Characteristics
• Insoluble in water = hydrophobic
• Functions: protect, insulate, provide energy
LIPIDS
Classes of lipids
Triglycerides
Phospholipids
Steroids based on ring-structure of cholesterol
Fat-soluble vitamins
- Most plentiful in diet and body
- Each composed of 3 fatty acids + 1 glycerol
- May be saturated, monounsaturated, or polyunsaturated
Triglycerides
form lipid bilayer in membranes
Phospholipids
Fat-soluble vitamins:
A, D, E, and K
Ring structures similar to
• Used to make steroid hormones
• Help make plasma membranes stiff
• Made in liver
CHOLESTEROL
Structure: composed of amino acids (monomers)
• 20 different amino acids (like alphabet)
PROTEINS
• Amino acid structure: central carbon with
- Acid (carboxyl) group (COOH)
- Amino group (NH2)
- Side chain (varies among the 20 amino acids)
Amino acids joined in long chains:
By dehydration synthesis to form
peptide bonds →
dipeptide → tripeptide → polypeptide
PROTEINS
• Functions (many)
• Much of cell structure • Contraction: muscle fibers • Regulate body: hormones • Transport of O2 in blood: hemoglobin • Defense: antibodies • Chemical catalysts: enzymes
• Proteins that serve as chemical catalysts
ENZYMES
• Highly specific: one works on a specific substrate →
product
• Efficient: can be used over and over
ENZYMES
\
\
- Names
- Most end in “-ase”
- Many give clues to functions: sucrase, lipase, protease, dehydrogenase
ENZYMES
- DNA or RNA
* Huge polymers composed of nucleotides
NUCLEIC ACIDS
• Each nucleotide (monomer) consists of
- Sugar (5-C monosaccharide: ribose or deoxyribose)
- Phosphate
- Nitrogen-containing (nitrogeneous) base
nitrogenous base:
• In DNA
adenine (A), guanine (G), cytosine (C), or thymine (T)
nitrogenous bases
• In RNA:
adenine (A), guanine (G), cytosine (C), or uracil (U) (which replaces
T of DNA)
• Nucleotides are connected into long chains that are bonded
by bases:
• C – G, G – C, T – A, or A – T
• Two chains form double helix (spiral ladder)
DNA
• Function: stores (genetic information) in genes (found in
chromosomes) that:
• Direct protein synthesis and therefore regulate everyday activities of
cells
• Carry this genetic information to the next generation of cells
DNA
• Nucleotides are connected into a long, single chain (one side of
a ladder)
RNA
In transcription, RNA (italics) positions next to
DNA: C – G, G – C, A - T,
or U – A
In translation, t-RNA (italics) positions next to
m-RNA (italics): C – G, G
– C, A - U, or U - A
• Function:
• Carries out protein synthesis by correctly sequencing amino acids, so
helps to regulate everyday activities of cells
RNA
Structure: composed of chemicals similar to those in RNA: base
(adenine), ribose, and phosphates
ATP
energy currency of living system
ATP
• Function: the main energy-storing molecule in the body
ATP
• contains 3 phosphates
• Carries energy in high-energy chemical bonds between terminal
phosphate groups
• Energy released from those bonds when they break: ATP → ADP +
phosphate + energy
ATP
