The organization of life – From atoms to the biosphere Flashcards
Definition of Life
Organization
Homeostasis
Metabolism
Growth
Adaptation
Responsiveness
Reproduction
organisation
Being composed of one or more cells- the basic unit of lie
homeostasis
Maintenance of a constant state - like constant glucose levels
Metabolism
Conversion of chemicals to obtain energy and cellular building blocks
Growth
Cells grow and divide
Adaptation
Ability to change - evolution
resposivness
Ability to respond to stimuli
Reproduction
The ability to produce new, individual organisms
Atoms and molecules
Atoms are the building blocks of molecules;
they can make covalent, ionic and hydrogen bonds.
Basic structure of an atmom
A nucleus in the middle containing protons and neutrons
Nucleus is surrounded by e-s orbital shells
Tye first orbital shell only holds mx 2 e-s
All other ones hold max 8 e-s
Negative atoms acquired an electron
Positive atoms lose an e-
How are the atoms/ elements classified?
Elements are classified by the no. of protons in atoms
All elements that dont have a full outer shell are reactive and try to fill their outer shell so they bons w other elements
A=Z+N
Protons + neutrons= atomic mass= usually mo. of e-s
3 types of chemical bonds
Covalent bonds
Hydrogen bonds
Ionic bonds
Covalent bonds
The sharing of a pair of valence e-s by two atoms
Come close and orbitals overlap
Non polar covalent bonds
The e-s are shared equally
The two bonding molecules have the same EN
Electronegativity
tendency of an atom to attract electrons
attraction of particular atoms for e-s of a covalent bond
Polar covalent bonds
When an atom like H is bonded to a more EN atom like O or N, the e-s of that bond are pulled more toward the O or N, creating partially + or partially - charge on the molecule
Some parts of the molecule become more - or +
Ionic Bonds
The transfer of an e- from one atom to other resulting in a positively charged atom (cations) and a negativly charged atom (anion) which attract eachother
Hydrogen bonds
Always involves Hydrogen
The attraction of a partially positive side of atoms to the partially negative side of other atom
Ex: water allies hydrogen to interact w all types of atoms
The most important biomolecules
are nucleic acids
Proteins
carbohydrates
lipids
Carbohydrates
sugars, monosaccharides (monomers, glucose ) and polysaccharides (polymers)
chains of C and H
Nucleic Acid (DNA, RNA)
consisting of 4 dif monomers (nucleotides)
Adenin, Guanin, Cytosine, Thymain (Uracil)
Lipids
fatty acids, mono lipids etc
Proteins
consisting of 20 dif monomers (amino acids)
Macromolecules
huge molecules (polymers) consitsing of viable number of coupled building blocks
