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161 Cards in this Set

  • Front
  • Back
Characteristics of life
Complex, organized structure
Response to stimuli - a change outside (or inside) leads to another change
Homeostasis - the ability to maintain the structure and regulate the internal environment.
Ability to acquire material and energy -The material and energy are often transformed
Growth
Reproduction - either sexual or asexual DNA is genetic information, the “blueprint” for the offspring
Ability to evolve - to change to fit the environment
ecosystem
A community together with its nonliving souroundings
community
two or more populations of different species living and the interaction in the same area
species
very similiar, potentially interbreeding organisms
population
members of one species inhabiting the same area
muticellular organisms
an indivisual living thing composed of many cells
organ system
two or more organs working together in the execution of a specific bodily function
organ
a structure usually composed of several tissue types that form a functional unit
tissue
a group of similiar cells that perform a specific function
cell
the smallest unit of life
organelle
a structure within a cell that performs a specific function
molecule
a combination of atom
atom
the smallest particle of an element thet retains the properties of the element
subatomic particle
particles that make up an atom
stimuli
Organisms react to external and internal stimuli.

Some reactions are slow and can’t be seen.
homeostasis
the ability to maintain the structure and regulate the internal environment.In order to stay alive and function, organisms must keep the conditions within their bodies fairly constant.
Ability to acquire material and energy
The material and energy are often transformed .
Energy is used to maintain a high level of complexity and organization, to grow, and to reproduce.
heterotrophs
Organisms can take in nutrients (food) for raw materials and energy
autotrophs
Or they can use sunlight for energy (photosynthesis) to produce energy-rich sugar molecules
Metabolism
is basically the sum total of all of the chemical reactions that occur within an organism.
Metabolism changes the raw material and energy into the forms which are needed for maintenance, growth, reproduction, etc .
evolution
If the environment changes, then the population of organisms must change to fit the environment or face the possibility of extinction.
mutation
The evolutionary changes are usually slow, taking several generations and occur by the accumulation of DNA changes known as
domains
Each of the major organizational groups are called
There are two prokaryotic domains;
Bacteria and Archaea and a eukaryotic domain; Eukarya.
kingdom
Within the domains are at least 6 groups known as
Each kingdom has different attributes which define them.
prokaryotes
-no nucleus or nuclear envelope
-genetic material in a "nucleoid region"
-no organelles or internal membranes
Eukaryotes
-nucleus w/ a nuclear envelope
-genetic material within the nucleus
-contains cytosol with membrane-bound organelles
bacteria-cell type, cell #, nutritional Method
prokaryotic
unicellular
absorb/photo
Archaea- Cell type, Cell #, NM
Pro
Uni
absorb/photo
protista- ct, c#, NM
eukary
uni
absorb/photo
fungi-ct,c#, NM
eukary
multi
absorb
plantae-ct, c#, NM
eukary
multi
photo
animalia-ct, c#, NM
eukary
multi
ingestion
The 3 most stable subatomic particles are
neutrons, protons, and electrons
protons
are positively charged particles found at the core, or nucleus, of the atom
neutrons
are uncharged particles found at the core, or nucleus, of the atom.
electrons
are light, negatively charged particles that orbit around the nucleus in electron shells
element
is a substance that can’t be broken down into other substances by chemical reactions
atomic weight
of an element is the number of protons plus the number of neutrons
isotopes
Isotopes are atoms of the same element which have different atomic weights (diff # pf protons and neutons)
electron orbitals
are the three-dimensional space around the nucleus of an atom where an electron will be found 90% of the time
The electron orbitals of an atom are arranged in _______ based on their ________.
electron shells
energy level
An atom with an incomplete (partially full) electron shell is ______ whereas an atom with a full electron shell is ____, or not chemically active
reactive
inert
chemical behavior of an atom is determined by
the number of electrons in the outermost electron shell
A chemical bond
is an attraction that holds two atoms together
A reactive atom will try to fill the valence shell by interacting with other atoms
a molecule
is two or more atoms held together by chemical bonds
The smallest unit that retains the physical and chemical properties of a compound
ions
is a charged atom or molecule. It is charged because it has either lost or gained electrons
If an atom has an almost empty or an almost full outer electron shell it is more likely to form an ion.
anion
is a negatively charged atom or molecule. It has gained an electron
cation
is a positively charged atom or molecule. It has lost an electron
A chemical bond is formed through
The gaining, losing, or sharing of electrons
After sodium loses an electron, it is
positive ion.
After chlorine gains an electron, it is
A negative ion
ionic compounds
Ionic compounds are called salts and usually form crystals as a solid.
Ionic bonds are strong in crystals but break easily in water.
covalent bond
is a bond formed when two atoms share pairs of electrons.
nonpolar covalent bond
ex H gas
same charge on both nuclei
electrons spend equal time near each nucleus
covalent bond is a covalent bond in which the sharing of the electron pair is equal
polar covalent
covalent bond is a covalent bond in which the sharing of the electron pair is unequal.
ex.water
electronegativity
defined as an atom’s ability to attract and hold electrons. Assigned a numerical value. The higher the #, the more electronegative an atom is

Hydrogen = 2.2
Carbon = 2.6
Nitrogen = 3.0
Oxygen= 3.4

Atoms with higher electronegativity have a more positively-charged nucleus, and will hold onto the electron pair more strongly than atoms with significantly lower electronegativity.
hydrogen bond
is formed by the charge attraction when a hydrogen atom which is covalently bonded to one atom is attracted to a second atom.
What kind of bonds form between water molecules?
hydrogen
hydrophillic
describes the property of having an affinity for water. easily dissolves in water
hydrophobic
describes the property of not having an affinity for water
Nonpolar substances
The polarity of water molecules makes water a poor solvent for molecules which do not have charged regions
hydrophobic interaction
hydrophobic molecules clump together in water because of
Water Molecules Tend To Stick Together
Water has cohesive behavior which is the result of hydrogen bonding between the water molecules and the other molecules and includes cohesion, and surface tension.
COHESION
Attraction between like molecules
Surface Tension
cohesion among water molecules at the surface of water
>>>Acids and bases Water molecules can
dissociate
hydrogen atom of one water molecule leaves its electron behind and forms a
hydrogen ion (H+) and a hydroxide ion (OH-)
dissociate
In pure water
the number of H+ ions = the number of OH- ions
If the solution is acidic
then the number of H+ ions is greater than the number of OH- ions.
solution is basic
if the number of OH- ions is greater than the number of H+ ions
An acid is a proton
proton donor, or a substance which increases the concentration of H+ in a solution.
base is a proton
acceptor, or a substance which reduces the concentration of H+ in a solution
pH scale
is a scale used to measure the acidity of solutions.

The scale ranges from 0 to 14.

For a neutral solution pH = 7
For an acidic solution pH < 7
For a basic solution pH > 7
Because the pH scale is a logarithmic scale
a change of one pH unit represents a tenfold change in the concentration of H+.
Most biological solutions are between
pH 6 and pH 8
Buffers
are substances that prevent large, sudden changes in pH.

Buffers are combinations of H+ donors and H+ acceptors

Buffers function by accepting H+ ions from solution when they are in excess, and donating H+ ions to the solution when the supply is depleted.


Example: Bicarbonate buffer
Three properties of water help keep temperature stable:
1) High specific heat
2) High heat of vaporization
3) High heat of fusion
Specific heat
is the amount of energy that must be absorbed or lost for one gram of matter to change its temperature by one degree Celsius.
Vaporization (evaporation
is the transformation of matter from a liquid to a gas.
Heat of vaporization
is the quantity of heat a liquid must absorb for 1 gram to be converted to the gaseous state, or to evaporate.


-Leads to cooling of the surface of a liquid when during evaporation.
Water has a high heat of fusion
Water has a high heat of fusion and freezes much slower than other liquids.

When water freezes, it forms an unusual solid, Ice which floats.
Organic molecules
are molecules containing carbon
except water
carbon atoms
Carbon atoms are the most versatile building blocks of molecules


Carbon has a valence of 4.
Can bind to 2, 3, or 4 other atoms.
Functional groups
are small characteristic groups of atoms which are frequently bonded to the carbon skeleton of organic molecules.
Another factor which leads to the versatility of organic molecules


Have specific chemical and physical properties.
Are regions of organic molecules which are frequently chemically reactive.
Behave consistently from one organic molecule to another.
Can determine the chemical properties of the organic molecule in which they are located.
Hydroxyl group
---Hydroxyl group is a functional group of a hydrogen atom bonded to an oxygen atom which is bonded to a carbon atom (of the carbon skeleton).
Is a polar group

-Involved in condensation (dehydration) and hydrolysis reactions
carbonyl group
Polar functional group.
Extremely hydrophilic.
Makes parts of a molecule water soluble.
Carboxyl group
Carboxyl group is a functional group in which a carbon atom is double bonded to an oxygen atom (like a carbonyl) and is also single bonded to the oxygen atom of a hydroxyl group.
Since this group can donate a proton, it is acidic
-Involved in peptide bonds between amino acids

-Since this group can donate a proton, it is acidic
-Involved in peptide bonds between amino acids
Amino groups
Amino groups are functional groups in which two hydrogen atoms are bonded to a nitrogen atom which is bonded to a carbon atom (of the carbon skeleton).


-Acts as a weak base (similar to ammonia) because it accepts protons.
-Involved in peptide bonds between amino acids
sulfhydryl (forms, found in)
Forms disulfide bonds within and between proteins.

Found in numerous proteins in biological systems.
A peptide bond forms between which two functional groups?
Carboxyl and amino
Phosphate group
Phosphate group is a functional group which is the dissociated form of phosphoric acid (H3PO4)
Acts as an acid because of the ability to donate protons.
-Links nucleotides together to form nucleic acids
-Important in cellular energy storage and energy transfer.
Example: ATP
Biological molecules are often put together in
Biological molecules are often put together in subunits, or modules, called monomers.

---the simple molecules combined to form more complex ones

---monomers into polymers
Polymers
are chains of similar building blocks or monomers.
-A Monomer
is a subunit (or building block) of a polymer.
The reaction that forms a polymer from monomers is
The reaction that forms a polymer from monomers is a dehydration synthesis (or condensation reactions).
Dehydration synthesis
is a reaction in which the covalent linkage of the monomers is accompanied by the “removal” of a water molecule.
Hydrolysis
is the breaking of the covalent bond between two monomers by the addition of water.
Carbohydrates
are used as fuels and building material
Carbohydrates are organic molecules made of sugars and their polymers.
Carbohydrates are classified by the number of simple sugars.
monosaccharides.
Monomers are simple sugars
carbohydrate
Monosaccharides are simple sugars in which carbon, hydrogen, and oxygen occur in the ratio of 1-2-1 for C, H, and O.
Major source of nutrients for cells. -Glucose is the most common -Can be produced by photosynthetic organisms from CO2, H2O, and light
Monosaccharides can be joined to form
disaccharides and polysaccharides
Disaccharides
are molecules which consist of two monosaccharides joined by a glycosidic linkage.
maltose
lactose
sucrose
Glycosidic linkage
is a covalent bond formed by a dehydration synthesis between two sugar monomers.
Each carbon has a hydroxyl group attached to it except one which is a
carbonyl group.
In aqueous solutions
monosaccharides with 5 or more carbons in the skeleton form ring structures.
The chemical equilibrium favors the ring structure over the straight chain
Polysaccharides
are macromolecules that are polymers of a few hundred or thousand monosaccharides.

Formed by enzyme-mediated condensation reactions.
-Biological functions Energy storage(starch and glycogen) (see fig 3-3) Structural support (cellulose and chitin) (see figs 3-4 and 3-5)

Formed by enzyme-mediated condensation reactions.
-Biological functions Energy storage(starch and glycogen) (see fig 3-3) Structural support (cellulose and chitin) (see figs 3-4 and 3-5)
Storage polysaccharide
Stored sugars can be hydrolyzed as needed. Stored in muscle and liver.
-Starch
is a glucose polymer that is used as a storage polysaccharide in plants.
---Glycogen
is a glucose polymer that is used as a storage polysaccharide in animals.
If there is more glucose in your bloodstream than your body needs, the excess glucose is linked together and stored as glycogen in your muscles and liver.

When energy is needed, glycogen is quickly broken down to release glucose into the bloodstream for short-term energy needs.

Once glycogen stores are full, excess glucose gets converted to fat for long-term energy needs.
Carb-loading
A process by which athletes are able to double or triple the amount of glycogen stored in their muscles. Used to delay the onset of muscle fatigue.

2 phase process:
Depletion phase- about a week before competition. Extremely low-carb diet and rigorous exercise.

Loading phase -2 days before competition. Super high-carb diet and no exercise. Achieves a blood glucose level that is higher than necessary, so excess glucose gets converted to glycogen.
Water Weight
The first stages of any diet usually involve rapid and dramatic weight loss.
Water is heavy 4-ounces to each molecule
Glycogen is nonpolar and does not deplete as fast (fat)

This is because glycogen is being depleted in the muscles and liver as caloric intake is reduced.

Every ounce of glycogen in the body can have as much as four ounces of water bound to it.
Structural polysaccharides include
cellulose and chitin
-Cellulose
is a linear unbranched polymer of glucose

most abundant organic molecule on the planet.

-differs from starch in the type of linkage
-different linkage gives different three-dimensional structure.
-cellulose reinforces plant cell walls.
Hydrogen bonds
hold the cellulose strands together-cellulose cannot be digested by most animals because they lack the enzyme that can hydrolyze the linkage in cellulose.
Chitin
is a structural polysaccharide that is a polymer of an amino sugar.

forms the exoskeleton of arthropods (insects, crawfish, etc.)
-found in the cell walls of some fungi.
Lipids
are mostly nonpolar hydrophobic molecules composed mainly of carbon and hydrogen
Lipids are a diverse group of organic molecules that are insoluble in water, but will dissolve in nonpolar solvents (e.g., ether, chloroform, benzene)
-Important lipids are grouped into 3 types:
1) fats, oils, and waxes 2) phospholipids 3) steroids.
Oils, Fats and Waxes
Characteristics:
-composed of carbon, hydrogen and oxygen
-contain 1 or more fatty acids
-usually no ring structure
--Fats and oils are
macromolecules constructed from fatty acids and glycerol.
---Glycerol
is a three-carbon molecule with one hydroxyl group per carbon.
Fatty acids (FA) are
hydrocarbon chains with a carboxyl group at one end
The hydrocarbon chain
or tail, is hydrophobic and not water soluble.
-The tail has a long carbon skeleton usually with an even number (16-18) of carbon atoms.
-The carboxyl group, or head, has the properties of a carboxylic acid.


The FA group is linked through the head to the glycerol and each hydroxyl group on the glycerol can form a linkage with a fatty acid.
Triglyceride
is a fat composed of three fatty acids bonded to one glycerol by
ester linkages.
Function of fats and oils:
Energy storage.
One gram of fat stores twice as much energy in its chemical bonds as one gram of polysaccharide.
-Because of the higher energy per gram, energy storage is more compact with fats and oils than with carbohydrates.
Olestra
Fake Fat”-designed to be similar to fats in taste and texture.

Cannot be digested by humans.

Instead of being a triglyceride with 3 fatty acids linked to a glycerol, it has 8 fatty acids attached to a molecule of sucrose.


It still stimulates the taste buds on your tongue that tell your brain that you are eating fat.

But because the molecule is so complex in shape, it prevents your body’s digestive chemicals from grabbing onto it and breaking it down.

Passes through your digestive system without being digested.
Fats
Humans store fat in
Fat also insulates
Fats exist as 2 main types
adipose tissue cells, which swell and shrink as fat is added to, or taken from them.

the body and protects vital organs.

: saturated and unsaturated.
SATURATED
No double bonds between carbons

Maximum number of hydrogen atoms bonded to the carbon of the skeleton (saturated)

Usually solid at room temperature

Most animals store fats
UNSATURATED
One or more double bonds between carbons

Chain kinks at each double bond, so individual chains cannot pack close enough together to solidify easily.

Usually liquid at room temperature

Most plants store oils
Waxes (linked to?,found in)
are similar to fats and oils except the fatty acids are linked to large, long chain alcohols instead of glycerol. Waxes are found in plants where waterproofing is needed and are used to build structures (i.e., beehives)
--Phospholipids
are compounds with molecular building blocks of glycerol, two
fatty acids, a phosphate group and usually a small chemical group attached to the
phosphate group.


Phospholipids have 2 ends that behave completely differently in water.

Hydrophilic heads and hydrophobic tails.

When phospholipids are added to water, they self-assemble into a bi-layer that shield their hydrophobic portion from water.
Steroids
Class of lipids that includes many hormones.

Characterized by a carbon skeleton consisting of 4 fused rings with various functional groups attached.

Includes cholesterol, a component of animal cell membranes. Used as a molecular precursor for many steroids
Proteins
are the molecular tools for most cellular functions.-Proteins are polymers of amino acids arranged in a specific linear sequence and are linked by peptide bonds.
Range in length from a few monomers to more than a thousand. -Each protein has a unique linear sequence of amino acids -Proteins are abundant, making up 50% (or more) of some cells dry weight.
Amino acids are joined into chains by
dehydration synthesis
Peptide bonds
are covalent bonds formed by a dehydration synthesis that links the carboxyl group of one amino acid to the amino group of
another amino acid.
Four levels of protein structure
Primary structure
Secondary structure
Tertiary structure
Quaternary structure (when a protein has more than one polypeptide chain)
-Important lipids are grouped into 3 types:
1) fats, oils, and waxes 2) phospholipids 3) steroids.
Oils, Fats and Waxes
Characteristics:
-composed of carbon, hydrogen and oxygen
-contain 1 or more fatty acids
-usually no ring structure
--Fats and oils are
macromolecules constructed from fatty acids and glycerol.
---Glycerol
is a three-carbon molecule with one hydroxyl group per carbon.
Fatty acids (FA) are
hydrocarbon chains with a carboxyl group at one end
The hydrocarbon chain
or tail, is hydrophobic and not water soluble.
-The tail has a long carbon skeleton usually with an even number (16-18) of carbon atoms.
-The carboxyl group, or head, has the properties of a carboxylic acid.


The FA group is linked through the head to the glycerol and each hydroxyl group on the glycerol can form a linkage with a fatty acid.
Triglyceride
is a fat composed of three fatty acids bonded to one glycerol by
ester linkages.
Function of fats and oils:
Energy storage.
One gram of fat stores twice as much energy in its chemical bonds as one gram of polysaccharide.
-Because of the higher energy per gram, energy storage is more compact with fats and oils than with carbohydrates.
Olestra
Fake Fat”-designed to be similar to fats in taste and texture.

Cannot be digested by humans.

Instead of being a triglyceride with 3 fatty acids linked to a glycerol, it has 8 fatty acids attached to a molecule of sucrose.


It still stimulates the taste buds on your tongue that tell your brain that you are eating fat.

But because the molecule is so complex in shape, it prevents your body’s digestive chemicals from grabbing onto it and breaking it down.

Passes through your digestive system without being digested.
Fats
Humans store fat in adipose tissue cells, which swell and shrink as fat is added to, or taken from them.

Fat also insulates the body and protects vital organs.

Fats exist as 2 main types: saturated and unsaturated.
SATURATED
No double bonds between carbons

Maximum number of hydrogen atoms bonded to the carbon of the skeleton (saturated)

Usually solid at room temperature

Most animals store fats
UNSATURATED (bonds,solid or liquid, ex)
One or more double bonds between carbons

Chain kinks at each double bond, so individual chains cannot pack close enough together to solidify easily.

Usually liquid at room temperature

Most plants store oils
Waxes
are similar to fats and oils except the fatty acids are linked to large, long chain alcohols instead of glycerol. Waxes are found in plants where waterproofing is needed and are used to build structures (i.e., beehives)
--Phospholipids(building blocks of, 2 ends)
are compounds with molecular building blocks of glycerol, two
fatty acids, a phosphate group and usually a small chemical group attached to the
phosphate group.


Phospholipids have 2 ends that behave completely differently in water.

Hydrophilic heads and hydrophobic tails.

When phospholipids are added to water, they self-assemble into a bi-layer that shield their hydrophobic portion from water.
Steroids
Class of lipids that includes many hormones.

Characterized by a carbon skeleton consisting of 4 fused rings with various functional groups attached.

Includes cholesterol, a component of animal cell membranes. Used as a molecular precursor for many steroids
Proteins
are the molecular tools for most cellular functions.-Proteins are polymers of amino acids arranged in a specific linear sequence and are linked by peptide bonds.
Range in length from a few monomers to more than a thousand. -Each protein has a unique linear sequence of amino acids -Proteins are abundant, making up 50% (or more) of some cells dry weight.
Amino acids are joined into chains by
dehydration synthesis
Peptide bonds
are covalent bonds formed by a dehydration synthesis that links the carboxyl group of one amino acid to the amino group of
another amino acid.
Four levels of protein structure
Primary structure
Secondary structure
Tertiary structure
Quaternary structure (when a protein has more than one polypeptide chain)
Amino acids
are monomer building blocks of a protein. Most consist of a central carbon with four functional groups:
Primary structure
is the sequence of amino acids in a protein. (see fig 3-20)

-Determined by the genes (DNA). -Different for each different protein -Determines all the remaining structure
--Secondary structure
is the coiling and folding of a protein’s polypeptide backbone. (caused by hydrogen bonding)
-Contributes to a protein’s overall conformation.
-Stabilized by hydrogen bonding between peptide linkages in the protein backbone
The major types of secondary structure are
helices and pleated sheets
---Tertiary structure
is the irregular contortion of a protein backbone due to bonding or interactions between side chains (R groups).

This third level of structure is superimposed on the primary and secondary structures.
Interactions of amino acid side chains
Covalent linkage
Disulfide bridges
Weak interaction
Hydrogen bonding
Ionic bonds
Hydrophobic interactions
Why is wet hair easier to style than dry hair?
Many proteins in your hair are held together by hydrogen bonds between the amino acids.

Adding water to your hair disrupts the hydrogen bonds between amino acids and causes them to hydrogen bond to water.

When your hair dries, hydrogen bonds can re-form between amino acids