Biology 12 unit1

Hydrophilic interactions

• Water loving

• involves polar compounds

• Water molecules orient around the sugar

• Sugar is soluble in water

Hydrophobic interactions

• Water fearing

• Involves nonpolar compounds

• Not soluble in water

• Water forms hydrogen bonds with other water molecules instead

• Water molecules exclude the oil molecules( All oil molecules are clustered together)

London forces

Even in molecules that have nonpolar covalent bonds there are always a chance accumulation of electrons in one part of the molecule or another (Since electrons are always in motion). Therefore, temporary areas of positive and negative charges occur. These Vander walls forces allow all molecules and atoms to attract one another.

Dipole dipole forces

Holds polar molecules together

Hydrogen bonds

• Strongest

• Occurs when a hydrogen atom covalently bonded to one electronegative is attracted to another electronegative atom

Ionic bonding

• Involves the transfer of electron

• Occurs between a metal and nonmetal with a large difference in Electronegativity between the two

• Results in ion charged atoms

• Achieve stable configuration for each atom

Polar covalent

• Electrons are shared unequally

• Bonding is affected by electronegativity the attraction of an atom for the electrons of a covalent bond

• Oxygen and nitrogen are very electronegative they pull electrons towards themselves

What is a valence and how many are there in hydrogen, oxygen, nitrogen and carbon?

• An atoms bonding capacity

• Hydrogen equals one

• Oxygen equals two

• Nitrogen equals three

• Carbon equals four

What are the diatomic molecules?

• H2

• N2-triple

• O2-double

• F2- g7

• Cl2-g7

• Br2-g7

• I2-g7

• G7(single covalent)

Covalent

• Nonmetals

• Same elements

• Different elements

• Sharing pairs of valence electrons by two atoms

• One to three pairs, maybe shared

• Achieve the stable configuration for each atom

Which bonds are weak And what type of bond are they?

intermolecular

• Hydrophobic and hydrophilic

• Hydrogen bond, dipole dipole

• London forces

Which bonds are strongest and what type of bonds are they?

Intramolecular bond

• Ionic metal and nonmetal

• Covalent nonpolar equal sharing polar not sharing

All other elements are usually found in molecular combinations. What are the three requirements?

1. It can gain one or two electrons from another atom

2. It can lose one or two electrons from another atom

3. It can share one or two electron pairs with another atom

What are three chemical properties that work when atoms combined to form molecules which group satisfies all these?

1. Tendency for electrons to occur in pairs

2. Tendency for atoms to balance positive and negative charges

3. Tendency for the outer shell of electrons to be full (8;octet rule)

   noble gases have all three

What are the 13 biological discoveries?

1. Microorganisms

2. Cell nucleus

3. Archea

4. Mitosis

5. Meiosis

6. Cell differentiation

7. Krebs cycle

8. Mitochondria

9. Neurotransmission

10. Hormones

11. Photosynthesis

12. Tropical biodiversity

13. Ecosystems

What are molecules?

• Two or more atoms connected can be the same type of atom or different atoms

What are elements?

Are made up of one type of atom

What are compounds?

Are two or more atoms connected together

What is chemical bonding?

An atom is the most stable with a full outer shell of electrons. Two electrons are eight electrons.

What is electronegativity?

Is the tendency for an atom to pull electrons towards itself

What is the octet rule?

An energy level of N equals three or higher, may not accommodate more than eight electrons when it is the outermost occupied energy level the valance shell

2n2 max #

What does the nucleus determine?

• Identity

• Behaviour

What is an isotope?

Atoms with the same number of protons but different number of neutrons, same atomic number but different mass

What is the order of heredity of matter?

1. Quarks

2. Subatomic particles like protons, electrons and neutrons

3. Atom

4. Molecules

5. Macro molecules like polysaccharides proteins, lipid/Fats and nucleic acids

6. Organelles

7. Cell

8. Tissues

9. Organs

10. System

11. Organisms

12. Populations

13. Communities

14. Ecosystems

What are buffers?

• Allow cells to resist significant changes in pH

• Except hydrogen from solution when they are in access

• Donates hydrogen atoms to the solution when they have been depleted

What is a base?

• A substance that increases the OH atom of a solution

• A substance that reduces the hydrogen atom of a solution

• A pH greater than seven

What is the range of pH for most biological fluids?

6-8

Blood-7.4

Dangerous- acidosis a drop in pH of 7.35, Alkalosis an increase in pH of 7.45

Lethal -7.0 and 7.8

What is an acid?

A substance that increases the Hydrogen atom of a solution

A pH of seven or less

The type of intermolecular force that must be overcome in order to melt ice into liquid water

Polar covalent

This keeps the phospholipid by layer of cell membranes in its usual orientation with the phospholipid tales oriented and words, and the phospholipid heads pointed towards the extracellular fluid on the one side towards the cytoplasm on the other

Hydrophilic and hydrophobic interactions

The bond one would expect to form between atoms of calcium (en=1.0)and chlorine(en=3.2)

Ionic

The Bond one would expect to form between two flooring atoms f2

Single non-polar covalent

The bond one would expect to form between two nitrogen atoms

Triple nonpolar covalent

The type of intermolecular force that must be overcome in order to melt solid iodine

London dispersion forces

The type of intramolecular force that exist in water

Polar covalent

The type of intramolecular force that exists in oxygen required to sustain most life on earth

Double nonpolar covalent

Water absorbs a lot of heat, giving it a high specific heat of vaporization H bonding causes liquid water to absorb a large amount of heat to become a gas

A dog pants too cool itself

Water is most dense at 4°C

Ice floats on liquid water, allowing fish to survive in winter

Many different substances, like sugar and alcohol, dissolve in water

Water is the universal solvent

This means glucose dissolved in water

C6H12O6 aq

This means that water molecules are forming each bonds with each other

Cohesion

Oil and gasoline both nonpolar substances dissolve well into each other

Like dissolves like

What is organic chemistry?

The branch of chemistry that specializes in the study of carbon compounds

Found in living organisms like carbohydrates, lipids, nucleic, acids, and proteins

What are the major elements of organic molecules?

Hydrogen

Oxygen

Nitrogen

Carbon

Describe carbon

Group 4 of the periodic table for valence electrons

A tendency to form for covalent bonds

Act as an intersection point in the large molecules

What are the variations in carbon skeletons?

• Very in length

• Straight or branched

• Even found in rings

• Single double or triple bonds

• May include atoms of either elements, hydrogen, nitrogen, or oxygen

Hydrocarbons

• Organic molecules, consisting of carbon and hydrogen atoms only

• Covalent bonds

• Not relevant in organisms, but as major components of the fossil fuel petroleum

What are the different types of hydrocarbons?

• Aromatic (contain a benzene ring and unsaturated)

• Aliphate (alkanes- single saturated 2n +2, alkene- double not saturated 2n, alkynes-triple not saturated 2n-2)

What are isomer’s?

Compounds that have the same molecular formula but different structure

What are the three types Of isomers

1. Structural

2. Geometric

3. Optical

What is a structural isomer?

Differ in the covalent arrangements of their atoms

What is a geometric isomer?

Have all the same covalent partnerships, but different in their spatial arrangements have in flexible, double bonds

What are optical isomer’s

Molecules that are mirror image of each other left and right handed versions of molecule. Usually one form is biologically active and the other is not.

What is the functional group of alcohols? R-OH

• Have a hydroxyl OH group

• The hydroxy group is polar sense. O is highly electronegative. Water molecules are attracted to the hydroxyl group.

• Name ends in OL

What is the functional group of carbonyl(c- -o)

Aldehydes

• The carbonyl Is on the end of the molecule

  Ketones

• The carbonyl Is not on the end of the molecule

What is the functional group of carbonic acid? R-cooh

Contains a carboxy group

Has acidic properties

What is the functional group amines (r-nh2)

• Contains an amino acid group

• The amino acid acts as a base

• Amino acids have a carboxy group and an amino group

What is the functional group thiols (R-sh)

• Compounds that contain a sulfhdryl group

• Generally smells like raw eggs

What is the functional group organic phosphates?

Contains phosphate groups

What are polymers?

Consist of many monomers, repeating subunits joined together

What are the macromolecules?

• Carbohydrates

• Lipids fats, steroids, waxes phospholipids

• Protein

• Nucleic acids

what are the monomers?

Monosaccharides, simple sugar like glucose

They vary

Amino acids

Nucleotides like phosphate, sugar base

What is dehydration synthesis?

• A process that links monomer together with the removal of water molecule

• A covalent bond joins the two monomers together

• Process requires ATP and enzymes

• It is anabolic

• It produces large amounts from smaller molecules

What is a hydrolysis reaction?

• A process which disassembles polymers into monomer

• Bonds between monomers are broken by the addition of water

• Example Starch is hydraulic size into monomer by the enzyme amylase in your mouth

• It is a catabolic reaction

• It breaks large molecules into smaller subunits

What is DNA?

Deoxyribonucleic acid instructions that program the cells activities contains the code for proteins And is double stranded

What are nucleotides?

Enzyme link nucleotides monomer together to form nucleic acid polymers by dehydration synthesis

What does one nucleotide include?

1. Nitrogenous Base

2. Pentose sugar

3. Phosphate group

   nitrogenous base and pentose sugar is a nucleotide

What is a polynucleotide?

• Many nucleotides are joined by covalent bonds, called phosphodiester linkage between the phosphate of one nucleotide and the sugar of the next monomer by the enzyme DNA polymerase

• Repeating sugar phosphate, backbone with base sticking out

What is DNA the double helix

• Discovered by James Watson and Francis crick

• Two polynucleotide chains spiralled around an Imaginary Axis

• The two strands are held together by hydrogen bonds between paired bases

• A-T C-G

What is a nitrogenous base?

• A nitrogenous base attaches to the deoxyribose sugar group

• There are two forms of nitrogenous bases Which Are purines and pyrimidines

What is the difference between purines and pyrimidines

Pyrimidines- t and c single ring

Purines- a and g double ring

What attaches one nucleotide to the other

phosphate Esther bond

The phosphodiester bond is the linkage between the 3 carbon atom Of one sugar, molecule, and the five carbon atom of the next

The bond creates polynucleotide

What are complementary base pairing?

Nitrogenous spaces on opposite strands pair through hydrogen bonds, forming Such that adding pears with thymine cytosine pears with guanine

A&T held by two hydrogen bonds

C&G held by three hydrogen bonds

What is chargaff’s rule

The amount of adding is equal to the amount of thymine

The amount of cytosine is equal to the amount of guanine

What are proteins?

• Proteins are the most diverse molecules in living organisms And among the most important

What are the functions of proteins?

Structural binding blocks

Functional molecules perform various tasks that aid in the bodies function

Examples are enzymes, haemoglobin collagen

Proteins are amino acid polymers

What are the three amino acid groups?

Polar

Nonpolar

Electrically charged

How many amino acids are there in total in which ones are essential?

There are 20 in total and eight of them are essential

What are structural proteins?

Linear arranged in sheet strands

What are globular proteins?

One or more polypeptide chains rounded spherical

What is the first level in globular proteins?

• Sequence of AAs in a polypeptide chain

• AAs equals residue

• From nucleotide sequence in DNA

What is the second level in Globular proteins

coils and folds due to amino acid and carboxy groups

Includes helix and pleated sheets

What is the third level in globular proteins?

• Strongest forces of attraction and repulsion between polypeptide and environment cause additional folding our group interaction

• Includes hydrophobic and Vanderwal interactions, polypeptide, backbone, disulfide, bridges, ionic bonds, hydrogen bonds

What is the fourth level in globular proteins?

Two or more poly peptides joined together to form a functional protein

What are proteins Constructed as?

In an equation environment at neutral pH in particular temperature

If environmental conditions change, it may unravel/de nature

What is denaturation and what causes it

Disrupts each bonds, ionic bonds, disulfide, bridges, and hydrophobic interactions

Caused by temperature pH and ionic concentration