Bio 23 Sections 3-4 Flashcards
What is a mixture?
It is substances that are physically blended but not chemically combined.
What percentage does water take up in the human body?
50-75% and that is based on age, sex, fat content, and so on.
Solvency
The ability to dissolve other chemicals
What is considered the universal solvent?
Water
Hydrophilic
A substance that dissolves in water and is referred to as polar or water-loving.
Hydrophobic
Substances that do not dissolve in water, are referred to be nonpolar or water-fearing.
Adhesion
The tendency of one substance to cling to another.
Cohesion
The tendency of like molecules to cling to each other.
For example, water is very cohesive due to the hydrogen bonds.
Chemical reactivity
The ability to participate in chemical reactions.
What does water ionize into?
H+ and OH-
What two synthesis reactions is water involved in?
Hydrolysis and dehydration
Heat Capacity
The amount of heat needed to raise the temperature of 1g of a substance by 1c degree.
Calorie (cal)
The amount of heat that raises the temperature of 1g of water 1c degree
Is water an effective coolant? True or False
True
How are solutions defined
1) solute particles under 1 nm
2) Solute particles do not scatter light
3) Will pass through most membranes
4) Will not separate on standing
Colloids in the body are often mixtures of what?
Protein and water
Colloids are defined by what physical properties?
1) particles range from 1-100 nm in size
2) scatter light and are usually cloudy
3) particles too large to pass through a semipermeable membrane
4) particles remain permanently mixed with the solvent when the mixture stands.
Suspension is defined by what physical properties?
1) Particles exceed 100nm
2) Too large to penetrate selectively permeable membranes
3) cloudy or opaque in appearance
4) separate on standing
Example blood cells in blood plasma
Emulsion
Suspension of one liquid in another
Example oil-and-vinegar dressing and fat in breast milk
Acid
Proton donor (releases H+ ions in water)
Base
Proton acceptor (accepts H+ ions and releases OH- ions)
Is a pH of 7.0 acidic?
False. It is neutral (H+ and OH- are the same)
Is a pH of greater the 7.0 a base?
True
What is a pH of less than 7.0?
Its acidic.
What are the chemical solutions that resist changes in the pH?
Buffers.
the change of one number on a pH scale is represented by how much change
Tenfold.
Example a pH of 4.0 is 10 times more acidic as a pH of 5.0
Electrolytes are crucial for what?
The heart, The nerves, and muscles
Electrolytes concentration is measured in equivalents. True of false?
True
Energy
is the capacity todo work, to move something. All body activity are forms of work.
Potential energy
Energy that us stored in an object, but not currently doing work.
Chemical energy
Potential energy in molecular bonds
Free energy
Potential energy available in a system to do useful work.
Kinetic energy
Energy of motion and doing work
Heat
Kinetic energy of molecular motion
Electromagnetic energy
Kinetic energy of moving packets of radiation called photons.
A process in which covalent or ionic bonds is formed or broken.
Chemical reaction
Symbolizes the course of a chemical reaction.
Reactants (on left) -> products (on right)
Chemical equation
How many classes of chemical reactions are there?
Four
Decomposition, Synthesis, Exchange, and Reversible reactions
What chemical reaction breaks down large molecules into two or more smaller ones?
Decomposition AB –> A+B
Synthesis Reaction
Two or more small molecules combine to form a larger one.
A+B –> AB
Two molecules exchange atoms or group of atoms.
AB+ CD –> ABCD –>AC+ BD
Exchange reaction
Reversible Reactions
Can go in either direction under different circumstances.
<–>
CO2 +H2O3 <–> H2CO3 <–> HCO3- +H+
Law of mass action
Direction of reaction determined by relative abundance of substances on either side of equation and equilibrium is reached when ratio of products to reactants is stable.
Law of mass action
Direction of reaction determined by relative abundance of substances on either side of equation and equilibrium is reached when ratio of products to reactants is stable.
When do reactions occur?
When molecules collide with enough force and correct orientation.
Reaction rates increase when?
The concentration of reactants is increased.
The temperature rises
A catalyst is present
Metabolism
a chemical reaction of the body
Catabolism
Energy-releasing decomposition reaction
Breaks covalent bonds
Produces smaller molecules
Anabolism
Energy-storing synthesis reaction
Requires energy input
Catabolism and anabolism are inseparably linked. true or false.
True
A chemical reaction in which a molecule gives up electrons and releases energy.
Oxidation
Molecules are oxidized when what occurs?
When they lose electrons
The oxidizing agent is?
The electron acceptors (oxygen is ofter the electron acceptor)
Reduction
Any chemical reaction in which a molecule gains electrons.
A molecule is reduced when what occures.
When a molecule gains electrons.
The reducing agent.
The molecule that donates electrons
Oxidation-reduction (redox) reactions
Oxidation of one molecule is always accomplished by the reduction of another.
Electrons are often transferred as hydrogen atoms.
Organic chemistry
The study of compounds containing carbon.
Carbohydrates
Lipids
Proteins
Nucleic acids
Carbon binds readily with each other and forms what.
A carbon backbone.
Functional groups
Form small clusters of atoms attached to a carbon backbone.
Determine many of the properties of organic molecules.
Hydroxyl
(-OH) Occurs in sugar, alcohol
Methyl
(-CH3) Occurs in fats, oils, amino acids.
Carboxyl
(-COOH) Occurs in amino acids, sugar, and proteins.
Amino
(-NH3) Occurs in amino acids and proteins.
Phosphate
(-H2PO4) and occurs in Nucleic acid and ATP
Macromolecules
Are very large organic molecules with high molecular weights.
Polymers
Macromolecules made of a repetitive series of identical or similar subunits ( monomers)
Polymerization
The joining of monomers to form a polymer.
Dehydration synthesis
Monomers covalently bind together to form a polymer.
A hydroxyl (-OH) group is removed from on monomer, and hydrogen (-H) from another.
Water is a by-product
Hydrolysis
The opposite of dehydration.
Splitting a polymer in monomers by addition of water
Carbohydrates are hydrophilic organic molecules. True or false
True
Monosaccharides
Are the simplest carbohydrates
Monomers
What are three important monomers
Glucose, Galactose, and Fructose. all have the molecular formula of (C6H12O6)
Disaccharides
Sugars that are made of two covalently bonded monosaccharides.
What are the three important disaccharides
Sucrose, lactose, maltose
Sucrose (table sugar)
Glucose + Fructose
Lactose (milk sugar)
Glucose + Galactose
Maltose (sugar in grain products)
Glucose + Glucose
Oligosaccharides
Short chains of three or more monosaccharides (at least 10)
Polysaccharides
Long chains of monosaccharides (at least 50)
Three important polysaccharides
Glycogen, starch, and cellulose
Glycogen
Is the energy that is stored in the cells of the liver, muscle, brain, uterus, and vagina.
Starch
Energy stored in plants that is digestible by humans
Cellulose
Structural molecules in plants that is important for human dietary fiber (but indigestible to us)
Carbohydrates are often conjugated with lipids and proteins. true or false
True
Lipids
Lipids are hydrophobic organic molecules with a high ratio of hydrogen to oxygen.
Five primary types of lipids in the human body
Fatty acids
Triglycerides
Phospholipids
Eilcosanoids
Steroids
Fatty acids
Chains of 4-24 carbon atoms with carboxyl groups on one end and a methyl groups on the other.
Must be obtained from food
What are the two groups of fatty acids
Saturated and nonsaturated
Triglycerides (neutral fats)
Three fatty acids are linked to glycerol and formed by dehydration and broken down by hydrolysis. The primary function is to store energy. oils and fats are examples
Trans-fatty acids
Two covalent single C-C bonds angle in opposite on each side of the C=C double bond. Resist breakdown and rise the risk of heart disease.
Cis-fatty acids
Two covalent single C-C bonds angle in the same direction adjacent to the C=C double bond.
Phospholipids
Similar to neutral fats except one fatty acid is replaced by a phosphate group.
Fatty acid tails are?
Hydrophobic (water- fearing)
Phosphate Heads are?
Hydrophilic (water-loving)
Eicosanoids
20-carbon compounds derived from arachidonic acid.
Hormone-like chemical singles between cells.
Include prostaglandins.
Do prostaglandins play important roles?
Yes! Inflammation, blood clotting, hormone action, labor contractions, blood vessel diameter.
Steroids
Lipids with 17 carbon atoms in four rings. Cholesterol
15% of our cholesterol comes from diet and 85% is from internal synthesized (mostly in the liver)
Other important steroids include:
Cortisol, progesterone, estrogens, testosterone, and bile acids.
HDL (high-density lipoprotein) Good or bad cholesterol
Good. A lower ration of lipids to proteins
may help prevent cardiovascular disease.
LDL (low-density lipoprotein) Good or Bad cholesterol
Bad. Has a higher lipid to protein ratio and contributes to cardiovascular disease.
