Module 2 Flashcards
Atomic number
the number of protons in the nucleus of an atom
-an atom usually has the same number of electrons as protons
Atomic mass
the sum of the number of protons and neutrons in the nucleus
Isotope
different atoms of the same chemical element that have the same number of protons but different number of neutrons
Heavy isotope
an isotope that contains more than the usual number of neutrons
these tend to be unstable and radioactive
cation
positively charged ions
anion
negatively charged ions
ion
an atom that has an electrical charge
molecule
a more or less stable grouping of two or more atoms held together by chemical bonds
compound
the combination of two or more different atoms
free radical
an electrically charged atom or group of atoms with an unpaired electron in its outermost shell
antioxidants
substances that deactivate oxygen-derived free radicals
covalent bond
a bond formed by atoms sharing electrons
electronegativity
the ability of an atom to attract shared electrons
polar covalent bonds
a covalent bond in which the two atoms have different electronegativities causing a separation of charges.
ex. water molecule
nonpolar covalent bonds
a covalent bond in which the two atoms have identical or very similar electronegativities so that the charges are distributed equally
ex. 2 hydrogen atoms
ionic bond
a bond formed by the transfer of electrons from one atom to another.
hydrogen bond
formed when a weakly positive hydrogen atom already bonded to one electronegative atom is attracted to another electronegative atom from another molecule
anabolic chemical reactions
form larger molecules from smaller molecules or atoms
catabolic chemical reactions
break the bonds between components of larger molecules to release smaller molecules or atoms
kinetic energy
the form of energy powering any type of matter in motion
potential energy
the energy matter possesses because of the positioning or structure of its components.
stored in the bonds between atoms and molecules
chemical energy
the form of potential energy in which energy is stored in chemical bonds
exergonic
chemical reactions that release more energy than they absorb
endergonic
chemical reactions that absorb more energy than they release
Why is water an essential component of life?
because it is able to break the ionic bonds in salts to free the ions
electrolytes
the electrical activity that derives from the interactions of charged ions
mechanical energy
directly powers the movement of matter
radiant energy
energy emitted and transmitted as waves rather than matter
electrical energy
contributes to the voltage changes that help transmit impulses in nerve and muscle calls, supplied by electolytes
All chemical reactions begin with
a reactant
reactant
one or more substances that enter a reaction
All chemical reactions result in
a product
product
one or more substances produced by a chemical reaction
the total mass of the reactants equals
the total mass of the products
synthesis reaction
occurs when two or more atoms, ions, or molecules combine to form new and larger molecules
A + B = AB
*requires energy
decomposition reaction
occurs when a molecule is broken down into smaller parts
AB = A + B
*releases energy
exchange reaction
occurs when both synthesis and decomposition occur and chemical energy is absorbed, stored, and released.
A + BC = AB + C
factors that influence the rate of chemical reactions (4)`
properties of reactants
temperature
concentration and pressure
enzymes/catalysts
how does temperature influence the rate of chemical reactions?
the higher the temperature, the faster the particles move, and the more likely they are to come in contact with each other
how does concentration and pressure influence the rate of chemical reactions?
the more particles present within a given space, the more likely those particles are going to bump into each other
catalyst
a substance that increases the rate of a chemical reaction without itself undergoing any change
enzyme
a catalyst composed of protein or RNA.
they lower the level of energy that needs to be invested in a chemical reaction.
activation energy
the threshold level of energy needed to break the bonds in the reactants.
oxidation-reduction reactions
electrons are taken from the atom being oxidized by the atom being reduced.
oxidation
the loss of electrons from a molecule, which results in a decrease in the potential energy of the molecule
Lose
Electrons
Oxidation
reduction
the gain of electrons by a molecule which results in an increase in the potential energy of the molecule.
inorganic compound
a substance that does not contain carbon and hydrogen
organic compound
contain both carbon and hydrogen, always have covalent bonds, and usually contain oxygen
What are the functions of water?
lubrication and cushioning
heat sink
components of liquid mixtures
How is water a heat sink?
Water absorbs the heat created by chemical reactions without greatly increasing in temperature itself.
When the environmental temperature increases, the water stored in the body keeps the body cool.
How do you calculate the concentration of solutes?
the number of particles of the solute in a given space.
How do you calculate molarity?
moles(atomic weight [M]) of the molecule per litre (L)
colloid
a mixture that is somewhat like a heavy solution.
the solute particles consist of tiny clumps of molecules large enough to make the solution opaque
suspension
a liquid mixture in which a heavier substance is suspended temporarily in a liquid but over time, settles out
Describe the structure of DNA
double helix
formed by deoxyribose
1 phosphate group
1 nitrogen containing base (ATGC) attached via hydrogen bond
What are the 4 chemical groups of an amino acid?
amino group
carboxyl group
r group
hydrogen
How does DNA and RNA differ physically?
DNA-double helix
RNA-a long strand
DNA- 2 backbones connected via hydrogen bonds
RNA- a single backbone with protruding bases
How does DNA and RNA differ chemically?
DNA-deoxyribose
RNA-ribose
DNA- carries purine (adenine and guanine) and pyramidine (thymine and cytosine) nucleotides
RNA- carries the same nucleotides but also a third pyramidine (uracil)
List the 4 elements that make up about 96& of our body weight
nitrogen
carbon
hydrogen
oxygen
What is the approximate pH of gastric juice?
2
What is the approximate pH of blood?
7.35-7.45
What is the approximate pH of milk of magnesia?
10.5
Define lipid
an organic compound primarily built from hydrocarbons, nonpolar, and non soluble in water
What are the 3 important types of lipids?
triglycerides
phospholipids
steroids
What is the function of a triglyceride?
they are fats and oils that contain nutrients
What is the function of phospholipids?
they make up the outer layer of the cell for protection
What is the function of steroids?
hormone building block
bile acid component
What are nucleotides?
an organic compound composed of:
one or more phosphate group
a pentose sugar (ribose/deoxyribose)
Define the term acid
a substance that releases H+ into a solution
Describe dehydration synthesis
one reactant gives up an atom of hydrogen and another reactant gives up a hydroxyl group (OH) in the synthesis of a new product
A molecule of water is released as a byproduct
Describe hydrolysis
a molecule of water disrupts a compound, breaking its bonds. The water itself is split into H and OH.
When are salts formed?
when ions form ionic bonds
What is a salt?
a substance that, when dissolved in water, dissociates into ions other than H+ or OH-
What is a strong acid?
compounds that release all of their H+ into a solution
What is a base?
a substance that releases OH- in a solution, or one that accepts H+ already present in a solution
What is a buffer?
a solution of a weak acid and its conjugate base
What is the pH of milk, urine, and saliva?
6.3-6.6
What are the organic compounds that are essential to life?
carbohydrates
lipids
proteins
nucleotides
carbon and hydrogen groupings are called
hydrocarbons
what is a functional group?
a group of atoms linked by strong covalent bonds and tending to function in chemical reactions as a single unit.
What are the important functional groups in human physiology? (5)
hydroxyl
carboxyl
amino
methyl
phosphate
Which functional group is a part of all essential organic compounds?
hydroxyl
What are included under the functional group carboxyl?
fatty acids, amino acids
What are included under the functional group phosphate?
phospholipids, nucleotides
what is a monomer
several copies of a single unit
what is a polymer
links of several copies of a single unit
What is a carbohydrate composed of?
carbon, hydrogen, and oxygen
CH2O
what is a carbohydrate reffered to as?
saccharide
What are the 3 types of carbohydrates/saccharides?
monosaccharide
disaccharide
polysaccharide
Give examples of monosaccharides
glucose, fructose, deoxyribose, ribose
Give examples of disaccharides
sucrose, lactose, maltose
Give examples of polysaccharides
starches, cellulose, glycogen
Where is glycogen stored
in the muscles and liver
What is ATP composed of
ribose, an adenine base, and 3 phosphate groups
what is a phospholipid?
a bond between the glycerol component of a lipid and a phosphorous molecule.
similar in structure to a triglyceride.
what is a phospholipid generated from?
a diglyceride
What is the structure of a phospholipid?
hydrophilic head: phosphate group and glycerol
hydrophobic tails: unsaturated and saturated fats
What is a steroid?
4 hydrocarbon rings bonded to a variety of other atoms and molecules
most important steroid is cholesterol
what are prostaglandins?
signaling molecules
derived from unsaturated fatty acids
sensitize nerves to pain
what are the functions of proteins?
give structure to the body
regulate processes
provide protection
help muscles to contract
transport substances
serve as enzymes
what is the structure of a protein
composed of amino acids linked by peptide bonds
all proteins contain N and many contain S, H, O, and C
what is an amino acid
a molecule composed of an amino group and a carboxyl group, together with a variable side chain
Amino acids consist of a central carbon atom bonded to: (4)
hydrogen atom
alkaline amino group NH2
acidic carboxyl group COOH
a variable group
what kind of bond holds together an amino acid?
peptide bond
what is denaturation?
a change in the structure of a molecule through physical or chemical means
what are enzymes
they speed up chemical reactions by increasing the frequency of molecule collisions, lowering the activation energy, and properly orienting colliding molecules
What are nucleic acids
huge organic compounds that contain C, H, O, N, P
basic units are nucleotides
what is DNA
deoxyribose containing
nucleotide that stores genetic code
ACTG
What is RNA
ribose containing
nucleotide that helps manifest the genetic code as protein
ACUG
What is a purine?
nitrogen-containing molecule
double-ring structure
Adenine and Guanine
What is a pyramidine?
nitrogen-containing base
single ring structure
Cytosine, thymine, uracil
What is ATP composed of?
a ribose sugar
an adenine base
3 phosphate groups
Why is ATP so high in energy?
the 2 covalent bonds linking its 3 phosphate groups store a significant amount of potential energy
Describe diffusion
the movement of particles from an area of high concentration to an area of low concentration until there is equal distribution
What is diffusion influenced by
distance
steepness of concentration gradient
temperature
size or mass of the diffusing substance
surface area
What is facilitated diffusion
the process used for those substances that cannot cross the phospholipid bilayer due to their size, charge, and/or polarity
ex. glucose into the cell
What is osmosis
the diffusion of water through the semipermeable membrane
What is isotonic
two solutions that have the same concentration of solutes
what is hypertonic
a solution that has a higher concentration of solutes than another solution
water molecules tend to diffuse into an hypertonic solution
what is hypotonic
a solution that has a lower concentration of solutes than another solution
water molecules tend to diffuse out of a hypotonic solution
What is active transport?
an energy-requiring process that moves solutes such as ions, amino acids, and monosaccharides against a concentration gradient
For each ATP molecule used, what moves into and out of the cell?
3Na+ move out
2K+ move in
what is endocytosis
the process of a cell ingesting material by enveloping it in a portion of its cell membrane and then pinching off that portion of membrane
vesicular transport
what are the 3 types of endocytosis
phagocytosis
pinocytosis
receptor-mediated endocytosis
what is phagocytosis
cell eating
what is pinocytosis
cell drinking
brings fluid containing dissolved substances into a cell through membrane vesicles
what is receptor-mediated endocytosis
endocytosis by a portion of the cell membrane that contains receptors that are specific for a certain substance.
once the surface receptors have bound sufficient amounts of the specific substance, the cell will endocytose the part of the cell membrane containing the receptor-ligand complexes
what is exocytosis
the process of a cell exporting material using vesicular transport
what is an example of exocytosis
immune cells releasing histamine
What is transcription
the process by which the genetic information encoded in DNA is copied onto a strand of RNA called mRNA which directs the protein synthesis.
The transcription of DNA is catalyzed by
RNA polymerase
What is translation
the process of reading the mRNA nucleotide sequence to determine the amino acid sequence of the protein
What is the sequence of translation
- rRNA and proteins form ribosomes
- specific amino acids attach to the molecules of tRNA. Another portion of the tRNA has a triplet of nitrogenous bases called anticodon.
- tRNA delivers a specific amino acid to the codon: the ribosome moves along an mRNA strand as amino acids are joined to form a growing polypeptide
