ch 2 Flashcards
what is chemistry
study of matter and energy
what is matter
has mass and occupies space
composed of elements
energy
power (or ability) to do work
elements
-fundamental (pure) form of matter
-cannot be broken down to a simpler form
- periodic table of elements
atoms consist of
Nucleus- has protons…have mass and pos charge neutrons…have mass, no charge
Shells (orbit)…electron…no discernible mass, negative charge
atomic number
number of protons, always the same number for any atoms of a particular element
atomic mass
roughly equal to number of protons plus neutrons
what is an electrically neutral atom
of protons= # of electrons
what is an isotope
atoms of the same element that have a diff number of neutrons…but a diff atomic mass
unstable isotopes-radioisotopes
what do radioisotopes give off
energy in the form of radiation
particles
they are unstable
uses of radioisotopes
dating fossils
diagnostic imaging
cancer treatment
power supply for implants such as cardiac pacemakers
free radicals are
-atoms or molecules with one or more unpaired electrons
- highly reactive
-can damage proteins and DNA
-may speed up cellular aging process
energy is
the capacity to do work
potential energy is
-stored energy
-potential energy can be transformed into kinetic energy
kinetic energy
energy in motion, doing work
if an orbital is further from the nucleus
the electrons with more potential energy
what happens when an electron absorbs energy
move to a shell father from the nucleus
what happens if an electron moves to a shell closer to the nucleus
it loses energy
in fluorescence light microscopy
- higher energy photons (blue wavelength) activate a fluorophore
- energized particles emits at a slightly lower energy state
what are chemical bonds
attractive forces holding atoms together
kinds of chemical bonds
-covalent bonds
- ionic bonds
- hydrogen bonds
what is a covalent bond
-sharing of electrons between atoms results in each atom having a maximally filled outermost shell of electrons
-strong
ex. hydrogen and oxygen in water
what is an ionic bond
-bond between two oppositely charged ions…permanent transfer of one or more electrons
-moderate
ex. Na+ and cl-
what is a hydrogen bond
contains covalently bonded hydrogen atoms
-weak
ex. bonds between molecules of water
what are the 6 elements that living organisms are composed of
*oxygen
* carbon-backbone of all organic molecules
* hydrogen
* nitrogen-components of proteins and nucleic acid
* calcium-bones, action of nerves and muscles
* phosphorus- part of cell membrane, constituent of bone
what does life depend on
water
why is water so important
*excellent solvent
*liquid at body temp
* absorb and hold heat energy
* evaporation of water uses heat energy
* is in essential chemical reactions
*BIOLOGICAL SOLVENT
*transports things in blood
solvent
*in a solution
* liquid in which other substances dissolve
solute
- in a solution
- dissolved substance
hydrophilic
*polar molecules-attracted to water and interact easily with water
hydrophobic
*non polar uncharged molecules that do not interact with or dissolve in water
how does water keep ions in a solution
*neg end of polar molecule is attracted to pos ions
*pos end of polar molecule is attracted to neg ions
*water molecules pulls ions away from crystal and prevent them from reassociating
water is the main constituent of
intracellular spaces
extracellular spaces
how does water help to regulate body temp
-absorbs and holds a lot of heat energy with only a slight increase in temp
*prevents rapid changes in body temp
*evaporation (sweat) cools the body off quickly
who developed thermoregulation
charles blagden
the link between sweating and thermoregulation
water in chemical reactions (2 ways)
*condensation- water producing
- joins carbs, proteins and lipids to make water
*hydrolysis-water breaking
- breaks carbs, proteins and lipids to consume water molecules
what is a hydrogen ion
a single proton without an electron
*one of the most important ion in body
what is an acid and the effect on hydrogen ion conc
*donates H+
* increases H+ conc
what is a base and the effect on hydrogen ion conc
*accepts H+
* decreases H+ conc
what scale expresses hydrogen ion conc
pH scale (express acidity or alkalinity)
acidic-less than 7
neutral=7
basic- greater than 7
higher [H+] lower pH and vice versa
what do organic molecules contain
- carbon and hydrogen
- has nitrogen, oxygen, phosphorus or sulfur
- held together by covalent bonds
what are the 4 organic molecules
carbohydrates
lipids
proteins
nucleic acids
what is the building block of organic molecule
carbon
what can carbon do
*4 covalent bonds
*single or double bonds
* can form linear, branched or ring shaped molecules
* can build micro or macromolecule
what does dehydration synthesis need/do
*requires energy
*removes water to link monomers
*builds polymers from monomers
*reverse of hydrolysis
what does hydrolysis do
*adds water molecule to breakup polymer
*releases energy
why are carbohydrates important
*energy source and structural support
what are monosaccharides and examples
*simple sugars
*glucose-energy source
*fructose
* galactose
*ribose-in RNA
* deoxyribose- in DNA
what is an oligosaccharide
more than one monosaccharide linked together
what type of rxn links monosaccharides
dehydration
what are disaccharides
two monosaccharides linked together
ex. sucrose-glucose+ fructose
maltose - glucose+ glucose
lactose- glucose +galactose
what makes up polysaccharides
thousands or monosaccharides joined in linear and/or branched chains
functions of polysaccharides
*stores energy
- starch…made in plants
- glycogen…made in animals
*structural support
-cellulose
types of lipids
triglycerides-energy storage molecules
phospholipids-cell membrane structure
steroids-carbon-based ring structures
lipids are
*insoluble in water
*they are the only macromolecule thats not assembled by joining monomers to from polymers
what are triglyceride
-energy storage molecule
-fats and oils
- glycerol bonded to 3 fatty acids
types of fatty acids
saturated (fats)- all single bonds between carbon
unsaturated (oils)- include some double bonds between carbons
where are triglycerides stored
adipose tissue
structure of phospholipids
- glycerol plus 2 fatty acids and phosphate group
- hydrophilic head
- hydrophobic tail
*primary component of cell membranes
steroids are composed of?
- 4 carbon rings
ex. cholesterol and hormones
what are proteins
*complex structures constructed of amino acids
*20 diff types
*has amino end, carboxyl end and R group
what are proteins composed of
long chains (polymers) of subunits (monomers) called amino acids
*joined by peptide bonds…produced by dehydration synthesis
*amino end, carboxyl end, R group
what is a peptide bond
forms between carboxyl end of one amino acid and amino group end of the next amino acid
what is a polypeptide
polymer of 3-100 amino acids
what is a protein
a polypeptide longer than 10 amino acids that has a complex structure and function
polypeptide amino acid chain contains
*a backbone with 2 ends (N-terminus and C-terminus)
*side chains containing amino acids
protein structures
*primary structure
-stabilized by peptide bonds
- amino acid sequence
*secondary structure
-alpha helix
-stabilized by hydrogen bonds
- beat pleated sheets
*tertiary structure
-3D shape
- combo of covalent bonds, ionic bonds, hydrophobic interactions, and hydrogen bonds
-creates polar and nonpolar areas within the protein molecule
*quaternary structure
- two or more polypeptide chains are joined
impact of denaturing proteins
-permanent disruption of protein structures…damaged by high temp or change in pH
- loss of biological function
what do enzymes do
*biological catalysts
- speed up chemical reactions
- not altered or consumed by the reaction
*important in homeostasis
what are enzymes composed of
protein
what is the shape of an enzyme dependent on
temp
pH
ion concentration
presence of inhibitors
what do nucleic acids store
genetic info
types of nucleic acids
DNA-contains the instructions for producing RNA
RNA- contains the instructions for producing proteins
info flow for nucleic acids
dna-rna-proteins
what are nucleotides and what are they made up of
*building blocks of nucleic acids
contains
- 5 carbon sugar (deoxyribose or ribose)
- nitrogenous base
- phosphate group
structure of dna
*double stranded
* deoxyribose sugar
*nitrogenous bases
Adenine-thymine
guanine-cytosine
(purine-pyridimine)
structure of RNA
*single stranded
*ribose
*nitrogenous bases
adenine-uracil
guanine-cytosine
what is ATP
*universal energy source
*bonds between phosphate groups that have potential energy
*breaking bonds released energy
-nucleotide: adenosine triphosphate
*ADP goes back to ATP if Pi is added
