Atoms are composed of protons neutrons and electrons These subatomic particles are charged Atoms make elements Elements cant be broken down into anything simpler Examples Carbon C ID: 701159
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Slide1
Atoms
Atoms are the basic unit of matterAtoms are composed of protons, neutrons and electronsThese subatomic particles are charged….Slide2
Atoms make elements… Elements can’t be broken down into anything simpler.
Examples:Carbon= CSodium = NaHydrogen= HNitrogen= NSlide3
Subatomic particles have specific locations…
Protons and the neutrons are found in the nucleus of the atom and electrons whizz around the outside of the nucleus
Electrons are
always
moving.
The atomic shell or orbital is the distance from the nucleus that the electron spins. Slide4
Valence shells…
The outermost shell is called the valence shell.
To be “happy” and full, the valence shell must have 8 electrons.
The electrons in the outermost shell are the only ones that react with other atoms
.
If the valence shell is full, the atom does not react.
Carbon only has four valence electrons (8 is the max) so carbon can bond with up to four other atoms. Slide5
Ions
A normal atom is neutral (same number of electrons and protons)Ions have a different number of electrons than the neutral atomSodium has only one valence electron… it would like to give that up so it can have a full outer shell.
Chloride needs one electron to have a full outer shell. Sodium loses an electron and becomes Na+
Chloride becomes negative when it gains an electron…
Cl
-Slide6
Bonding= trying to be a happy, FULL atom
Some atoms can easily lose electrons to be full
Some atoms can easily gain electrons to become fullSlide7Slide8
Ionic bonds
A good example of an ionic bond is NaCl.Sodium really wants to lose an electron and becomes a positive ion
(cation). Chloride really wants to gain an electron (high electronegativity) and becomes a negative ion (
anion
).Slide9
Covalent bonds
If the two atoms have partially fill shells then the two atoms will probably just share the electrons. A good example of this methaneSlide10
More covalent examplesSlide11
Polar Covalent Bonds
Polar Covalent means that two atoms share electrons but the electrons may spend a majority of their time with one particular atom. (joint custody)An example: WATERSlide12
Hydrogen Bonds
The hydrogen ends of water are slightly positive because the electrons spend most of their time with oxygen.
This means that the H’s are attracted to the O’s of other water molecules. The dotted lines show hydrogen bonds forming.
Hydrogen bonds form in other molecules like DNASlide13Slide14
MACROMOLECULES important to living things!
_____________
_____________
_____________
_____________
Carbohydrates
Lipids-
fats, oils, waxes steroids
Proteins
Nucleic acidsSlide15
Introductory Terms
Macromolecule = “giant” molecule of living matterMonomer = subunits that are the building blocks of a polymer
Example: Lego blockPolymer = monomers linked togetherExample: Lego castleSlide16
Macromolecular Reactions
Dehydration Synthesis:2 monomers become bonded to each other to make a polymerLose water
Hydrolysis:
Water is used to break up polymers into monomers
Using water to break bondsSlide17
Carbohydrates
Structure:C:H:O in a 1:2:1 RatioExample: C
6H12O6 which is glucose
Functions:
Short-term
energy-
-
Pasta dinner before the big race, game, etc.
Structural SupportSlide18
Lipids
Structure:Made up of carbon, hydrogen, and a few
oxygensDo not dissolve in waterFunctions:
Long-term energy storage
Chemical messengers (hormones)
Insulation around your nerve cells and to keep you warm!
Waxes (plant leaves to prevent water loss)Slide19
Lipids-Triglycerides
FatsMade of glycerol and 3 fatty acids tails
Connect via dehydration synthesis to make triglycerides Triglycerides are fat molecules… clogging arteries…Slide20Slide21
___________________
(lipid tails + glycerol/phosphate head)
PHOSPHOLIPIDS
Polar head
Non-polar
tailsSlide22
Lipids
SteroidsMade up of 4 interconnected ringsExamples:
CholesterolTestosteroneEstrogenSlide23
Proteins
Most of a cell is made up of proteinsInstrumental in almost everything organisms do
Structure:All proteins are created from unique combinations of 20 different amino acids
C,H,O,N (S)
Major Functions:
Structure
Defense (antibodies)
Enzymes- we will discuss these later!Slide24
Proteins
Amino AcidsAmino acids are the monomers of proteins
Organic molecules possessing both carboxyl and amino groups ( get it AMINO…. ACID)
20 types of AAs that make up 1000s of different proteins
AAs are linked together by peptide bonds to make polypeptidesSlide25Slide26
Proteins
Denaturation
:When pH, salt concentration, temperature, and/or other environmental factors are altered, the protein may unravel and lose its shape
Biologically inactive
Structure + functionSlide27
Nucleic Acids
StructureMade of a chain of Nucleotides
Nucleotides are made of a sugar, a phosphate and a nitrogen baseFunction
Carries genetic material from one generation to the next
Builds RNA and DNASlide28
NUCLEOTIDES
2 SUGARS can be used:
DEOXYRIBOSE for DNA
RIBOSE for RNASlide29
5 NITROGEN BASES
Adenine= A
Guanine= G
Cytosine= C
Thymine = T (only in DNA)
Uracil
= U (only in RNA)
A,G=
Purines
C,T,U=
pyrimidinesSlide30Slide31
RNA vs. DNA
RNASugar is riboseContains Uracil not Thymine
Single stranded DNASugar is
Deoxyribose
Contains A,T, C, G
Double strandedSlide32
ONE SPECIAL KIND of NUCLEOTIDE is used by
cells to store and transport energy!
ATP
Sugar =_____________
Nitrogen base =__________
+___ PHOSPHATE groups
That’s why it is called adenosine
tri
phosphate
RIBOSE
ADENINE
3Slide33
When you use up energy or ATP…Slide34
ATP ADP Cycle
So, ATP has three phosphates but energy is released when ATP turns to ADP by losing a phosphateHydrolysisCycles back and forthSlide35
Cohesion
Water sticks to water (hydrogen bonds)Helps plants transport water through vesselsSlide36
Adhesion
Water sticks to other molecules (like the side of a glass) Also helps keep water moving up against gravity in plants. Slide37
Surface Tension
Related to cohesionMolecules resist being pulled apart due to strong hydrogen bonds… form a “film”Slide38
Density
Why can’t you fill a water bottle completely when you want to freeze it?What occurs to the structure of water when it freezes?Insulation for life below the surface…Slide39
pH Scale- ever heard of it?
An acid is a compound that releases protons (H+) when dissolved in water A base is a compound that adds OH- when dissolves in water.We measure the these reactions on the pH scale Slide40
The pH Scale- ranges from 0-14
pH of 1 means lots of H+ ions and SUPER ACIDICpH of 14 means lots of OH- (or low H+) and SUPER BASICWater is neutral with a pH of 7Slide41Slide42
Enzymes are special proteins