Unit 3: Chemistry of Life

What is the monomer of a carbohydrate?

monosaccharide

Catalyst

a substance that speeds up the rate of a chemical reaction without being changed by the reaction

Activation energy

the minimum amount of energy needed to cause a process (chemical reaction) to occur

Active sites

binds to the enzyme to undergo a chemical reaction

Fatty acid

a hydrocarbon (a carbon chain with hydrogen atoms attached and a carboxyl group at the end)

Solvent

the substance is the dissolving medium

Solute

the substance that is dissolved

Unused carbohydrates are converted into…

lipids

What is the structure of a carbohydrate?

the shape of a carbon ring

Carbohydrates are made of which elements?

carbon, hydrogen, and oxygen

What are the functions of carbohydrates in cells?

used as the main source of energy (sugar), and sometimes for structural purposes (cellulose, which help make cell walls and structures)

What are some examples of carbohydrates?

sugar, starch, glucose

What is the monomer of a lipid?

glycerol and 3 fatty acids

What is the structure of a lipid?

the shape of a letter E (glycerol backbone and 3 fatty acids)

Lipids are made of which elements?

carbon, hydrogen, and oxygen

What are the functions of lipids in cells?

used to store energy, for protection, insulation, and buoyancy (also regulates what goes in and out of cells)

Are lipids soluble in water?

no, they don’t like water (they are water repellent)

What are some examples of lipids?

fats, oils, waxes

What are steroids?

(a lipid) they are specific chemicals that regulate our body and homeostasis

Saturated

has the maximum number of hydrogen atoms (solid at room temperature, and its structure has straight lines)

Unsaturated

there is at least one double bond in the fatty acid (liquid at room temperature, its structure has crooked lines, and its better for our body because it is easier to digest)

What is the monomer of a nucleic acid?

nucleotide

What is the structure of a nucleic acid?

3 parts; 5-carbon sugar ring, nitrogenous base (5 different bases), phosphate group

Nucleic acids are made of which elements?

carbon, hydrogen, oxygen, nitrogen, and phosphorus

What are the functions of nucleic acids in cells?

used to store and transmit hereditary/genetic information

What are examples of nucleic acids?

DNA, RNA, ATP

What is the function of DNA?

it has the information to make proteins

What is the function of RNA?

it makes the proteins

What is the function of ATP?

it is made from carbohydrates (but is a nucleic acid) and provides energy

What is the monomer of a protein?

an amino acid

What is the structure of a protein?

has an amino group (NH2), carboxyl group, and a side chain (COOH)

Proteins are made of which elements?

carbon, hydrogen, oxygen, and nitrogen

What are the functions of proteins in cells?

hemoglobin carries oxygen in blood, enzymes are biological catalysts (they lower the activation energy, so it takes less energy and time for chemical reactions to occur), builds up muscles and tissues, and structural support

How many amino acids are there?

22 kinds

What are examples of proteins?

hemoglobin, enzymes, keratin, collagen, albumin (from eggs), meat

What happens when proteins are heated up?

they can break down and the structure changes

Equilibrium

when things are in balance

Endothermic reactions

it takes in energy, feels cold

Exothermic reactions

it releases/creates heat, feels hot

Most chemical reactions are…

exothermic

Chemical reactions

they release or absorb energy involving the breaking and forming of bonds

Metabolic reactions

chemical reactions that occur in a cell/in your body

Enzymes

speeds up the rate of a chemical reaction, lowering the activation energy

What affects enzymes?

temperature and pH

Organic

is alive and contains carbon

Why is the carbon atoms a good element?

it has 4 valence electrons, allowing it to bond with many elements (including itself)

What are buffers?

weak acids or bases that can react with strong acids or bases to prevent sudden changes in pH, keeping it stable

Where is water on the pH scale?

7 (middle of the scale, meaning neutral)

What is the range of the pH scale?

0 to 14

More acidic solutions are ____ on the pH scale

lower

More basic solutions are ____ on the pH scale

higher

Acids contain…

higher concentrations of H⁺ (hydrogen) ions than water

Bases contain…

higher concentrations of OH^- (hydroxide) ions than water

How do acids taste?

sour

How do bases taste?

bitter (typically, and is slippery)

What is a weak acid?

vinegar

Density

less dense substances float on denser substances

Cohesion

when water sticks to itself (because of hydrogen bonds)

Adhesion

when water sticks to other stuff

Surface tension

hydrogen bonding creates something like a net, allowing much denser things to float on water

Capillary action

when water adheres to the fiber of a paper/plant and pulls up another water molecule

Universal solvent

water can dissolve many other substances because of its polarity

High specific heat

water can hold heat for a long time (slow to heat, slow to cool)

Solution

all components are evenly distributed throughout (AKA homogeneous mixtures)

Suspension

a mixture of undissolved materials/substances, where each substance can be visibly separated (AKA heterogeneous)

Hydrogen bonds are formed when…

the partial positive and negative charges of the water molecule attract other water molecules (opposites attract), forming weak bonds

Which bond is the weakest?

hydrogen bonds

Which bond is the strongest?

covalent bonds

Covalent bonds are formed when…

electrons are shared by atoms

Ionic bonds are formed when…

one or more electrons are transferred from one atom to another (they give/gain electrons to each other), creating an electrical attraction between these two oppositely charged atoms/ions

Compounds

made of two or more different elements

Noble gases

these elements are very stable, because their outer electron shells are completely full

Ion

an atom or molecule that has a charge other than zero (has a positive or negative charge)

Isotope

an atom of the same element with a different number of neutrons in the nucleus, making it unstable

Cation

positively charged ion

Anion

negatively charged ion