- capture solar energy and convert it into a useable form of chemical energy
- chemical energy can be used to sustain the growth or can fuel energy requiring reactions
- travels to the earth in particles called photons.
- photons have different wavelengths, different energies.
- necessary for living organisms
- used for photosynthesis.
- plants can't use light until it is absorbed.
- other accessory pigments can absorb other wavelengths that chlorophyll a can't, then pass it on to a.
1: light behaves as a wave
2: distance between the peaks of two consecutive waves is measures as the wavelength. the wavelength tells us the color of the light and is measured in nanometers.
1: absorption: light energy is retained by pigment molecules. only type of light
2: reflection: bounces back
3: transmission: passes through object
- photo reaction: only with light present. chlorophyll converts energy of photons into electron energy (chem. bonds in ATP)
- synthesis reaction: can occur in light and dark. incorporates inorganic carbon in co2 into organic carbon in sugars.
- energy of position
the ability of an object or system to do work.
- work takes place when a force moves an object a distance
1: energy is always conserved (not created anew or destroyed.)
2: energy can be transferred through interaction of forces between objects
3: energy transfer is never 100% efficient. a small amount of heat is always released (due to motion of atoms and molecules.)
natural energy sources that regenerate
- heat and light from sun, motion of water and wind, biomass, heat from earth's surface
natural energy sources that do not regenerate
- petroleum, natural gas, coal, nuclear
- photosynthesis (sun+co2+h2o) , stored chemical energy (glucose)
- aerobic respiration (mitochondria)- usable chemical energy (ATP)
- circulates throughout cell- energy "currency" of cells.
-more saturated, more c-h.
-tend to be solid ta RT
- less saturated, more c=c
- tend to be liquid at RT
- burn other molecules for fuel.
- burn fats and amino acids for fuel during aerobic repiration
- digested food subunits leave small intestine- enter bloodstream- taken up by cells in body.
- bloodstream also transports dissolved o2 from air
- occurs in the cytoplasm
- series of enzymatic reactions in the cytoplasm that break down sugar into smaller carbon units.
- releases a small amount of chemical energy, converted into the bonds of ATP
-occurs in mitochondria
- releases energetic electrons from short carbon chains.
- small amount of ATP is made and co2 is released from the cell.
- occurs in the mitochondria
- produces bulk of ATP
- oxygen accepts e, then combines with hydrogen to produce water.
- potential energy is mostly conservedinte h transfer from glucose to ATP, but some heat is lost
- glycolosis occurs but its products go to a different process.
- occurs in cytoplasm
-quick bursts of energy
when oxygen is scarce
- matter is conserved during fermentation, but less energy is produced w/o oxygen.
- hereditary molecules
- formed from nucleotides linked into long polymer strands
- in the cytoplasm
- no chromosomes
- DNA not coated in proteins
- multiple, linear chromosomes
- DNA coated in proteins
- DNA is wrapped around histones which forms chromatin
- chromatin helps make DNA smaller and denser, helps package it so it fits.
- a chromosome consists of a single DNA molecule wrapped around proteins
- chromosomes are only visible in microscope during mitosis
- three smaller molecules held together by covalent bonds
- phosphate, sugar, base
- A: adenine
- T: thymine
- G: guanine
- C: cytosine
- each protein is encoded in DNA in a length of sequences termed a gene
- regulatory sequence: controls timing, location, and amount of gene expression
- coding sequence: determines the sequence of amino acids in the protein
- nucleus of eukaryotes
- cytoplasm of prokaryotes
- cytoplasm on ribosomes
(free or in rough ER)
-RNA polymerase transcribes DNA code (gene) in mRNA for (message) in the nucleus
- RNA polymerase binds regulatory sequence
- the DNA strands unwind, exposing the gene coding sequence (template strand)
-RNA poly. moves along one DNA strand, reading the DNA coding sequence and synthesizing a complementary mRNA strand-
- complete RNA leave nucleus.
- the mRNA attaches to the ribosome
- during translation the ribosome "reads" the mRNA message and assembles a chain of amino acids.