AP Bio Unit 1

Atom

Smallest unit of matter that retains the properties of an element, made of subatomic particles

Proton

Found in an atom's nucleus and has a positive charge

Neutron

Found in an atom's nucleus and has a neutral charge

Electron

Rapidly moves around the nucleus and has a negative charge

How do electrons form chemical bonds between atoms?

Either by sharing or transferring electrons between atoms

What are electron arranged into?

Electron shells

Which electrons have the highest potential energy?

Those furtherest from the nucleus

In atoms, electrons interact forming _____?

Chemical bonds

Covalent bonds

Strong bonds that form when atoms "share" their valence electrons

What are the different types of covalent bonds?

single, double, and triple bonds

Polar Covalent Bonds

Electrons spend more time around the more electronegative atom→one atom being more positively charged and the other being more negatively charged

Electronegativity

How much an atom "wants" electrons. High electronegativity=Wants a lot of electrons

Nonpolar covalent bonds

When electrons are shared equally resulting in a molecule without a charge

Ionic bonds

A strong bond between atoms when electrons are stolen from one atom and then transferred to another atom

Hydrogen bond

A weak attraction between a partially positive hydrogen atom and a partially negative atom with nitrogen, oxygen, or fluorine

Where is the hydrogen bond located?

BETWEEN molecules NOT atoms

Van der Waals interactions

Occurs when atoms are extremely close together and the positive and negative charges have a weak attraction towards each other

Reactants

A starting material in a chemical reaction

Products

Ending materials in a chemical reaction.

What type of molecule is water?

a polar molecule

In a water molecule what atom has a partially negative charge?

Oxygen

In a water molecule what atom has a partially postive charge?

Hydrogen

Where do hydrogen bonds in water form?

Between the partially positive hydrogen of one molecule and the partially negative of another molecule

Cohesion

When water molecules stick together

Adhesion

When water molecules stick/adhere to something else

Capillary Action

When water molecules adhere to the sides of a narrow material and coheres with the other water molecules

What does capillary action result in?

Water flowing upwards

surface tension

This occurs through cohesion when water molecules stick together and form a film across the surface of the water

Water's High Specific Heat

Water can absorb large amount of heat before changing temperature, allowing it to maintain a relatively constant environment

Water's High Heat of Vaporization

Water is able to absorb a lot of heat before it evaporates

What does it mean that water is less dense as a solid than as a liquid?

This means that ice can float and it ensures that a pond won't completely freeze, protecting the environment beneath it

What does it mean that water is a universal solvent?

Water is a universal solvent meaning that it can dissolve almost anything

Solvent

Substance doing the dissolving

Solute

Substance being dissolved

Solution

Mixture of the dissolved substances

Aqueous solution

A solution that has water as a solvent

Why is water such an excellent solvent?

Because its charged regions associate with the opposite charged regions on the other molecule, breaking it apart and surround the solute in hydration shells

Hydrophilic

water loving

What types of substances are hydrophilic?

ionic or polar substances

Hydrophobic

Water repellent

What types of substances are hydrophobic

Nonpolar

Mole

What is used to measure the concentration of molecules in a solution of water

Molarity

The number of mole of solute per liter of solution

pH

Represents the concentration of hydrogen ions (H+) in a water solution

What type of scale is pH represented on?

A logarithmic scale that goes 0-14

Where on the pH scale is neutral?

7

Where on the pH scale is acidic?

0

Where on the pH scale is basic?

14

When a solution is basic what ions do they have more of?

hydroxide ion (-OH)

When a solution is acidic what ions do they have more of?

Hydrogen ion (H+)

Why is carbon great at forming bonds?

Because it has four valence electrons

What electrons control the bonds an atom forms?

Valence electrons

Valence electrons

Electrons in the outermost shell

Organic compound

anything containing carbon

Hydrocarbons

Compounds composed of only carbon and hydrogen

What are the most important elements found in living things?

Carbon, Hydrogen, Nitrogens, Phosphorus, Sulfur

What elements do carbohydrates have?

Carbon, hydrogen, oxygen (CHO)

What elements do lipids have?

carbon, hydrogen, oxygen (sometimes phosphorus if phospholipid) (CHO[P])

What elements do proteins have?

Carbon, Nitrogen, Hydrogen, Oxygen (CHON)

What elements do nucleic acids have?

Carbon, Nitrogen, Oxygen, Phosphorus, Hydrogen (CHONP)

Elements in the hydroxyl group

Oxygen, hydrogen (-OH)

Elements in the carbonyl group

Carbon, oxygen (CO double bond)

Elements in the carboxyl group

Carbon, two oxygen, hydrogen (-COOH)

Elements in the amine group

Nitrogen, two hydrogen (-NH2)

Elements in the Sulfhydryl group

Suflur and hydrogen (-SH or -HS)

Elements in the phosphate group

Phosphorus, 3 oxygen (1 oxygen that has a double bond to the phosphate)

Elements in the methyl group

Carbon, 3 hydrogen (-CH3)

Monomers

Repeating subunits that make up polymers

Polymers

A long chain thats made of repeating subunits (Monomers)

Dimer

When two monomers come together

What does the building up of molecules create?

Covalent bonds

What does the breaking down of molecule break?

Covalent bonds between molecules

Metabolism

The set of all life-sustaining chemical reactions in an organism

Catabolic Reactions

Chemical reactions that break down complex molecules into simpler ones

Anabolic reactions

Chemical reactions that build new more complex molecules from simpler ones

Enzymes

facilitate in metabolic reactions and are an almost universal type of protein that are essential because they help to speed up chemical reactions by lowering the activation energy for the reaction

Dehydration synthesis (condensation reactions)

When two monomers are bonded together as one loses an -OH and the other loses an -H and a covalent bond forms between the two monomers. The loss of the -H and -OH forms a water molecule

What type of reaction is dehydration synthesis?

Anabolic

Hydrolysis

When a polymer is broken apart by adding a water molecule at the covalent bond between them, attaching -OH to one monomer and an -H to another.

What type of reaction is hydrolysis?

Catabolic reaction

Monosaccharides

The monomers that make up carbohydrates

Polysaccharides

Many monosaccharides are bonded together

Glycosidic linkages

The covalent bonds that form between monosaccharides

What is the ratio of carbon, hydrogen, and oxygen?

1:2:1 ratio

What structure are carbohydrates arranged into?

Rings or linear forms

Carbohydrates functions

Energy extraction, Energy storage, Structural material

Traits of glucose

Great for energy transfer since it is stable and soluble in water

High potential energy that can be oxidized to form ATP

Fructose

Monosaccharide often found in fruit

Lactose

Disaccharide made of glucose and galactose

Found in milk

Can be broken down by the enzyme lactase

Glycogen

Polysaccharide used for energy storage in animals, fungi, and bacteria

What is the purpose of glycogen?

Great for storing away energy for quick use at a later time

Where is glycogen stored?

Vertebrate store glycogen in their liver and muscles

Starch

Polysaccharide used for energy storage in plants

What is the purpose of starch?

Great for storing away energy for quick use at a later time

Where is starch stored?

Plants store starch in their chloroplasts, roots, tubers, and seeds

Cellulose

Polysaccharide used for structure in plants

What organisms cannot digest cellulose?

Animals

Chitin

Polysaccharide used for structure in arthropods and fungi

What are the functions of cellulose?

Builds the arthropods exoskeleton, builds the cell walls in fungi

Lipids

Macromolecule that doesn't have true monomers or polymers BUT they all share being hydrophobic