Chapter 2 - The Chemistry of Life Flashcards
Understanding chemical elements within the body
acid
pH lower than 7 - a chemical compound that disassociates in solution releasing hydrogen ions and lowering the solutions pH
element
a substance who’s atoms all contain the same # of protons & electrons (causing the atom to be neutral)
atomic theory
John Dalton - 5 points (1. all matter is made of atoms, 2. atoms of a given element are similar to one another, 3. atoms of two or more elements form compounds, 4. a chemical reaction involves the re-arrangement, separation, or combination of atoms, 5. atoms are never created or destroyed in chemical reactions)
Protons
have a positive charge - one unit of atoms weight
Neutrons
are neutral in charge - one unit of atoms weight
Electrons
have a negative charge - practically weightless - determining all of the atoms chemical and physical properties (except mass and radioactivity)
Atomic Number
indicates the number of protons or electrons - the number of protons (atomic number) also determines it’s location on the periodic table
Orbitals
energy levels - is the location of electrons in respect to the nucleus - first orbital has a max. capacity of 2 electrons, all the rest have a max. of 8
Isotope
atoms of the same element but have different numbers of neutrons (ie: C 12 has six protons & neutrons, C 13 has six protons & seven neutrons, C 14 has six protons & eight neutrons)
Molecule vs. Compound
A molecule is formed when two or more atoms (either the same or different) of an element chemically join together. ie: O2 (oxygen)
Water is both: molecule & compound H2O
A compound forms if the types of atoms are different from each other
Ion
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons
Ionic Bond
one atoms gains electron(s)
while the other donates electron(s)
are extremely polar & will dissolve in water
often crystaline
Covalent Bond
atoms SHARE electrons (not always equally though) to fill the outermost energy level - they do not dissociate when immersed in water
The 5 most important elements found in cells that bond covalently: Carbon, Oxygen, Hydrogen, Nitrogen and sometimes Sulpher
Hydrogen Bond
a weak bond between two molecules (one which contains hydrogen) resulting from an attraction between a proton in one molecule and the electrons in the other
Electrostatic force
the electrons of each atom are attracted to the protons of the other - like charges repel, opposites attract
Polarity - slightly positive vs. slightly negative
THE TAKER is negatively charged - now has more electrons than protons
THE GIVER is positively charged - now has more protons than electrons
ie: H+ 2 O- or Na+ Cl-
Electronegativity
the relative power of an atom/molecule to attract electrons to share - the higher the number, the more attracted electrons will be
Electron carrier
special molecules that gain electrons only to lose them to another molecule in a very short time
ENERGY
ALL BONDS - contain energy (the ability to do work) - results from the interaction of electrons and the nuclei of the bonded atoms
amount of energy varies as the distance between the atoms changes
If atoms are close, the electron paths overlap
Bond Length
the distance between 2 nuclei at the point of minimum energy (balance between attraction and repulsive forces)
Double Bond
a bond in which 2 pairs of electrons are shared by a pair of atoms
Calculate based on valence electrons (outermost orbital for entire molecule)
Carbon = 4
Oxygen = 6 x 2 = 12
16 total
each oxygen will need to share 2 electrons to fulfill carbon (bond) and the carbon will need to share 2 of its electrons with each oxygen to fulfill (bond #2) drawn as
. . . .
: O = C = O :
Adenosine Triphosphate
ATP - high energy fuel molecule that is constantly being broken down and built up to do the cells work
Created by adding a phosphate group (PO 4) to Adenosine Diphosphate (ADP)
Common Living Substances in Living Systems
10 of them - CAMP CALM NW Carbon Dioxide Gas Ammonia Molecular Oxygen Proteins Carbohydrates Adenosine Triphosphate (ATP) Lipids Mineral Salts Nucleic Acids Water
Water - Roles
Most abundant sub. in living cells - makes up and 60% to 80% (91% in plasma)
- Takes part in respiration (glucose used to create ATP) and photosynthesis (creates glucose)
- Solvent for chemical reactions
- Aids in digestion (break down of larger molecules)
- Basis for transport in blood (hormones & enzymes)
- Base for lubricants (mucus & synovial fluid)
- Helps control body temp.
- Protection (fetus in amniotic fluid and brain in cerebrospinal fluid)
Phototsynthesis - compound formation
6 CO2 + 12 H2O = C6H12O6 + 6 O2 + 6 H2O
Respiration - compound formation
C6H12O6 + 6 O2 = 6 CO2 + 6 H2O + energy (in the form of ATP)
Carbon Dioxide - CO2
covalently bonded - necessary for photosynthesis to convert radiant energy into usable chemical energy (glucose) - expelled from the body as a waste of cellular respiration
Molecular Oxygen - O2
covalently bonded - approx 21% of the gas in the atmosphere is oxygen and produced by photosynthesis in plants - required to convert energy (glucose) into usable energy (ATP)
Ammonia - NH3
covalently bonded - the Nitrogen is an important element in amino acids (building blocks of proteins)
comes from decomposition of proteins through the digestive process and conversion of amino acids to ATP
ammonia is injurious to cells and the liver converts it to urea for disposal
Mineral Salts (aka Electrolytes) - functions
composed of ions
- are involved in structure of enzymes & hormones
- are portions of cellular env. necessary for enzyme or protein actin
Mineral Salts (aka Electrolytes) - List 7 Major
Seven Major ones:
Calcium (Ca+) - muscle contraction, nervous transmission, strong bones (most abundant)
Phosphate (PO4-) - ATP production
Chloride (Cl-) - nervous transmission
Potassium (K+) and Sodium (Na+) - muscle contraction and nervous transmission
Magnesium (Mg+) - enzyme systems
Sulfur (S+) - not yet taught
Carbohydrates
covalently bonded - Carbon, Hydrogen, Oxygen in 1:2:1 ratio Think sugar (3 bonded groups - monosaccharides, disaccharides, polysaccharides)
Provide energy, store energy, and strengthen cells (cellulose in plants and chitin in external skeleton of arthropods)
Monosaccharides
a carbohydrate - one sugar - will not react with water into anything simpler
H-C-OH is typical for sugars
chains of either
5 carbon (Ribose in RNA or deoxyribose in DNA)
6 carbon (Glucose (6 atom ring) or Fructose (5 atom ring) atoms
Disaccharides
a carbohydrate - 2 sugars - water is released between the two and an oxygen bond is formed
examples are
Sucrose - Comb. glucose & fructose
Lactose - Comb. glucose & galactose
Maltose - Comb. glucose & glucose
Polysaccharides
a carbohydrate - many sugars
examples are
starch - can be used as energy or stored as glycogen
cellulose - matl. of plant cell walls - fiber in our diets
glycogen - animal starch
Glycogen
a type of carbohydrate - polysaccharide of glucose that serves as a form of energy storage
Lipids
insoluble in water - mostly non-polar bonds
Energy storage
Insulation - found under skin
Protection - surrounding kidneys to shield from severe jolts
Examples are:
fats, phospholipids, steroids, prostoglandins in molecular form
Glycerol
aka glycerin - is a simple compound that is the backbone of triglycerides (a fat) - only a 3 carbon chain (hydroxyl group is -OH)
colorless, odorless, viscous liquid that is sweet-tasting and non-toxic
Triacylglycerol
trī-ăs′əl-glĭs′ə-rôl′
a type of fat (lipid) found in your blood
Make up 95% of the fats in our bodies
Combines glycerol to 3 fatty acid chains (releasing water and forming an O bond)
eat - body converts any calories it doesn’t need to use right away into triglycerides (stored in your fat cells) Later, hormones release triglycerides for energy between meals
Fatty acids
a compound that is connected to glycerol to form triacylglycerols - a long carbon/hydrogen chain that ends in a carboxyl group (-COOH)
Glucose
Carbohydrate - a type of sugar you get from foods you eat, and your body uses it for energy
Saturated Fatty Acid
Lipid - saturated in hydrogen bonds
usually solid at room temp.
ingesting too many can lead to cardiovascular disease
Unsaturated Fatty Acid
Lipid - unsaturated in hydrogen bonds meaning the carbon chain has at least 1 double covalent bond between the carbon atoms
usually liquid at room temp.
are good for you
Steroid
Lipid - a hormone with a backbone of 4 interconnected carbon rings
Phospholipid
Lipid - Made up of glycerol, 2 fatty acids, and on the 3rd carbon of glycerol is a phosphate group
Make up cell membrane walls (think 2 legged octopus) with hydrophobic ends facing inwards (legs) and hydrophilic ends facing out (their head)
Protein - made up of
Contain C, H, O, N and some S
Amino acids are building blocks
- hydrogen atom
- carboxyl group (-COOH)
- amine group (-NH2) aka amino
- the “R” group
Protein - functions
- Structure - part of plasma membrane, Endoplasmic reticulum, Mitochondria and muscle cells (actin & myosin)
- Energy - like carbs & lipids are broken down & converted to ATP
- Immunity - antibodies are proteins
- Hormone proteins - coordinate bodily functions
- Transport proteins - hemoglobin transports oxygen in the blood
Primary structure
Proteins 1st determining factor for structure - the sequence of the amino acids
Peptide Bond
a chemical bond formed between two molecules
the carboxyl group of one amino acid and the amino group (NH2) of another amino acid bond and release water (similar to when sugars combine in disaccharides of carbs.)
Enzymes
catalyst - accelerate chemical reactions
are typically proteins
Nucleic Acid
general names - DNA & RNA
large molecules made of: C, O, H, N & phosphorous atoms (dbl or single chains of nucleotides)
DNA - Stores our genetic instructions (chromosomes)
RNA - molecules that are necessary for protein synthesis
Nucleotide
basic structure of a nucleic acid
consists of :
a nitrogen base (one of four chemicals: adenine, thymine/uracil, guanine, and cytosine)
a molecule of sugar (deoxyribose or ribose)
phosphoric acid (phosphate group)
Secondary structure
proteins 2nd determining factor in structure
coil or pleat (determined by the hydrogen & amino acid interaction) - is crucial to the functioning of proteins
if hydrogen bonds are destroyed (high temp or increased acidity) the protein becomes non-functional
stabilized by hydrogen bonds
Tertiary structure
proteins 3rd determining factor in structure
“balling” up - folding caused by interactions within the peptide bonds and between sulfur atoms of different amino acids (changes affecting this structure also affect protein function)
hydrophobic packing
stabilized by hydrogen bonds
Quaternary structure
proteins 4th determining factor in structure
determined by spatial relationships between individual units
Ribonucleic Acid
Three major types of RNA
1. mRNA, or messenger RNA, that serve as temporary copies of the information found in DNA
- rRNA, or ribosomal RNA, that serve as structural components of protein-making structures known as ribosomes
- tRNA, or transfer RNA, that ferry amino acids to the ribosome to be assembled
Purine
two carbon nitrogen base - represented by 2 hexagons attached by two hydrogen bonds
- Adenine (DNA or RNA) - will attach to T/U
- Guanine (DNA or RNA) - will attach to C
Pyrimidine (pie-rim-i-deen)
one carbon nitrogen base - represented by 1 hexagon
- Thymine (DNA only)
- Uracil (RNA only)
- Cytosine (DNA or RNA)
Adenosine Triphosphate - functions
fuel that runs the cells machinery - currency for intra-cellular energy transfer
- structural repair
- reproduction
- assimilation (absorption & digestion of food)
- transporting matls across cell membranes
- plays important role in synthesis of nucleic acid
Adenosine Triphosphate - components
ATP is made of
- Ribose (5 carbon sugar represented as two hexagons)
- Adenine (purine)
- Three phosphate groups (the energy is stored in the 2nd and 3rd phosphate groups)
ADP + PO4 + energy = ATP
Adenosine Diphosphate - components
ADP is made of
- Ribose (5 carbon sugar represented as two hexagons)
- Adenine (purine)
- Two phosphate groups (the energy is stored in the 2nd group)
when combined with a 3rd phosphate group and energy you get ATP
Cellular Respiration
a set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products
Diffusion
movement of molecules from an area of high concentration to an area of low concentration - random collisions of molecules
What factors affect molecular speed?
Temperature - the warmer, the faster
Solids are slowest while gases are fastest
Give an example of diffusion in the body
We breathe in air which is oxygen rich
O2 diffuses to the blood from the lungs
CO2 moves from the blood to lungs
Exhale to release CO2
Osmosis
Pertains to the movement of water molecules
Hypertonic
a solution that is high in H2O. Distilled water.
Hypotonic
a solution that is low in H2O. Maybe you have salt dissolved in the water.
Active Transport
Cells obtain materials that will go against the concentration gradient
ATP is required
pH
a scale of acidity from 0 to 14. It tells how acidic or alkaline a substance is with 7 being neutral
acidic
if when the substance dissociates, there is an excess of Hydrogen
the more H+ ions, the stronger the acidity
0 is most acidic, and 6.9 is least
Alkali (basic)
a substance combines with the Hydrogen in water, thus lowering the H+ concentration
7.1 is the least basic and 14 is the most
Buffer
a substance that acts as a reservoir for Hydrogen ions. It will donate them or take them “in” as required to help maintain homeostasis
Most buffers contain one acid and one base
Blood contains: bicarbonate (base) and carbonic acid (acid)
Amine group
contains nitrogen - H2N
formed from ammonia (NH3) by replacing one or more of the hydrogen atoms - to build an amino acid, to build a protein
