Lesson 2: Chemistry Of Life

Question 1

Element

Answer 1

A pure substance that cannot be broken down into simpler substances by chemical means

Ex. Oxygen, Hydrogen, Carbon, etc.

Question 2

Atom

Answer 2

Basic ☆building block☆ for all matter in the universe

Question 3

Molecule

Answer 3

The simplest unit of a chemical substance, usually a group of two or more atoms

Ex. Water: H2O, Oxygen: O2, Ozone: O3

Question 4

Compound

Answer 4

A type of molecule in which the types of atoms forming the molecule are ☆different☆ from each other. (Not all molecules are compounds)

Ex. Salt: NaCl, Water: H2O

Question 5

Nucleus

Answer 5

The central part of an atom made up of protons and neutrons

Question 6

Proton, Neutron, Electron

Answer 6

Proton: particle with a positive charge in the nucleus of an atom with a greater mass than electrons

Neutron: particle with a neutral charge in the nucleus of an atom with mass equal to that of a proton and electron combined

Electron: particle with a negative charge with a mass smaller than that of a proton or neutron

Question 7

Polar Molecule

Answer 7

A covalently bonded molecule that unequally shares its electrons and has a “negative” and a “positive” end

Ex. Water (H2O) has an unequal distribution of electron charge

Question 8

Non-Polar Molecule

Answer 8

A covalently bonded molecule that equally shares its electrons and has no “negative” or a “positive” end

Ex. Methane (CH4) has an equal distribution of electron charge

Question 9

Hydrogen bonds

Answer 9

Where polar molecules get weakly bonded between their slight + and - ends

Occur in biologically important compounds. Ex: water, DNA, and proteins

Question 10

Covalent Bonds

Answer 10

A strong bond that forms from sharing an electron pair between two atoms

Question 11

Properties of Water

Answer 11

1. Cohesion/Adhesion
2. Water’s high specific heat
3. Ice is less dense than water
4. Transparency
5. Water is the universal solvent

These exist because water is a polar molecule and it has hydrogen bonds

Question 12

Cohesion

Answer 12

Hydrogen bonds help ☆water molecules stick together☆; responsible for surface tension (minimizing suface area) and capillary action (process of a liquid flowing into a narrow space without or in opposition to gravity).

Ex. Helps plants absorb water through their roots

Question 13

Adhesion

Answer 13

Allows water to ☆stick to many other surfaces☆; responsible for surface tension (minimizing suface area) and capillary action (process of a liquid flowing into a narrow space without or in opposition to gravity).

Ex. Allows blood to flow through tiny vessels in some animals

Question 14

Water’s High Specific Heat

Answer 14

Water takes a lot of energy to heat or cool, giving it a high specfic heat (the amount of energy needed to raise 1 gram of a substance 1 degree Celcius).

Ex. Regulates Earth’s temperature, keeping it in a moderate range

Question 15

Ice is Less Dense than Water

Answer 15

When water freezes, it expands into a lattice that makes it less dense than water, causing it to float (there are less molecules in the same volume).

Ex. Floating ice allows life to exist in the bottom of a body of water

Question 16

Transparency

Answer 16

The fact that water is clear allows sunlight to pass through it.

Ex. Aquatic plants can recieve sunlight and photosynthesize

Question 17

Water is the Universal Solvent

Answer 17

Allows living things (who are mostly made of water,) to dissolve the variety of compounds they need for life (cells, blood, tree sap, etc.)

Ex. Helps animals dissolve the mutrients they need to survive

Question 18

Monomer

Answer 18

A small organic molecule

Question 19

Polymer

Answer 19

A type of macromolecule that is a large/long chain (organic molecule) of connected monomers

Question 20

Dehydration (Condensation/Synthesis)

Answer 20

Assembles monomers into polymers (by removing H2O and energy is stored)

Helps build our bodies

Question 21

Hydrolysis

Answer 21

Disassembles polymers into monomers (H2O is added and energy is released)

Helps break down food

Question 22

Macromolecules

Answer 22

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids

Question 23

Carbohydrates

Answer 23

Monomer: Monosaccharide
Polymer: Polysaccharide
Function: Short-term energy, growth
Examples: Glucose, Sucrose, Starch
Food: Rice, pasta, fruit
Atoms: C, H, O

Question 24

Lipids

Answer 24

Monomer: Fatty Acid and Glycerol
Polymer: Triglyceride
Function: Long-term energy, storage, structure
Examples: Steroids, cell membranes, wax
Food: Oil, butter, nuts, avocados
Atoms: C, H, O

Question 25

Proteins

Answer 25

Monomer: Amino Acids
Polymer: Polypeptide
Function: Build cells and structure, control enzymes and reactions (everything but energy)
Examples: Structure, muscle, antibodies, transport, enzymes, hormone signaling
Food: Meat, soy, milk
Atoms: C, H, O, N, (S)

Question 26

Nucleic Acid

Answer 26

Monomer: Nucleotide
Polymer: Nucleic Acid (polynucleotide)
Function: Instructions/code for genetic information, building proteins
Examples: DNA, RNA
Atoms: C, H, O, N, P

Question 27

Carbs vs. Lipids

Answer 27

Carbs have a 2:1 ratio of H to O.

Question 28

Saturated Fats vs. Unsaturated fats

Answer 28

Saturated fats don’t have double bonds.

Question 29

Enzymes

Answer 29

proteins that “catalyze” chemical reactions in cells (biological catalysts)

Question 30

Catalyst

Answer 30

Something that speeds up a chemical reaction

Question 31

Substrate

Answer 31

a reactant which binds to an emzyme to start a reaction

Question 32

Substrate specific

Answer 32

The ability of an enzyme to choose exact substrate from a group of similar chemical molecules.

Question 33

Active Site

Answer 33

A pocket on the surface of an enzyme that fits the substrate.

Question 34

Activation Energy

Answer 34

The amount of energy that a chemical reaction needs to start.

Question 35

Lock and Key

Answer 35

Enzymes and substrates that fit together like a lock and key show the specificity of enzymes

Question 36

Induced fit

Answer 36

The way the active site changes shape to “embrace” the substrate

Question 37

How do enzymes speed up chemical reactions?

Answer 37

Enzymes (a catalyst) lower the activation energy necessary for chemical reactions.

Question 38

Structure of an enzyme substrate interaction

Answer 38

The substrate enters the active-site of an enzyme and forms an enzyme substrate complex. The products then leave the active site.

Question 39

Factors impacting enzyme activity:

Answer 39

1. Temperature (Heat)
2. pH
3. Substrate Concentration
4. Enzyme Concentration
5. Inhibitors

Question 40

Temperature (Heat)

Answer 40

☆ More energy = more molecular movement (kinetic energy)
☆ As temperature increases, collisions between substrates and enzyme active site increase
☆ However, to much heat denatures (destroys) enzymes

Question 41

pH

Answer 41

☆ Too low/high pH will denature enzymes
☆ All enzymes have a pH range depending on their location in the body (usually 6-8; 1-2 for stomach enzymes)
☆ Has an optimum then rate decreases

Question 42

Substrate Concentration

Answer 42

☆ Reaction rate increases until all enzymes are busy breaking down substrate

Question 43

Enzyme Concentration

Answer 43

☆ Increasing enzyme concentration allows more interactions with substrate molecules
☆ Increases the rate of the reaction until no additional substrates can be found

Question 44

Inhibition

Answer 44

☆ Competitive inhibition - competes for the active site (the inhibitor fills the active site which prevents the reaction from occuring and slows it down)

☆ Non-competitive Inhibition - competes for the “allosteric” site and changes the shape of the active site so the substrate can’t bind to it

Question 45

Enzymes involved in digestion (and where they are produced):

Answer 45

Pepsin: made in stomach; found in stomach; digests proteins
Trypsin: made in pancreas; found in small intestine; digests proteins
Amylase: made in salivary glands and pancreas; found in mouth and small intestine; digests carbs
Lipase: made in pancreas; found in small intestine; digests lipids

Question 46

Mouth

Answer 46

☆ Teeth - Mechanical Digestion
☆ Salivary Glands - secrete amylase for carb digestion
☆ Tongue - Moves food from mouth to esophagus
☆ Epiglottis - flap to cover trachea (windpipe) when swallowing

Question 47

Stomach

Answer 47

☆ Esophagus - tube transporting food from mouth to stomach
☆ Stomach Acid - Eliminates pathogens/bacteria, makes food dissolve
☆ Muscles - mix food
☆ wavy texture - constantly reproducing
☆ Pepsin - enzyme; breaks down proteins

Question 48

Perstalsis

Answer 48

The contraction of muscles throughout the digestive system to move food throughout the body.

Question 49

Acids and Alkali

Answer 49

☆ Stomach produces HCI (hydrochlroic acid)
– Kills Bacteria;
– Needed for pepsin to function
☆ Alkali (bases)
– Bile is produced by the liver;
– Used to digest lipids

Question 50

Small Intestine

Answer 50

☆ Chemical breakdown of food using accessory organ enzymes
☆ Nutrients are absorbed into the bloodstream
☆ Liver produces bile to digest lipids
☆ Bile is stored in the gallbladder and injected into small intesines when needed
☆ Pancreas injects more enzymes for digestion
☆ Trypsin - digests proteins
☆ Amalyse - digests carbs
☆ Lipase - digests lipids
☆ Absorption of fat - solubale vitanmins take place (Vitamin A,D,E,K)

Question 51

Large Intestine

Answer 51

☆ At this point, most nutrients are absprbed from our food and the watse is a liqud mash
☆ Water is removed from the waste
☆ Water soluable nutrients are absorbed (Vitamin B + K)
☆ The rectum stores waste at the end of the large intestine until it is ready to exit the body through the anus

Question 52

The Role of Bacteria in Digestion

Answer 52

☆ Good bacteria live in our intestines to assist in digestive processes.
☆ They help us digest starches, fibers, sugars, and vitamins.
☆ They keep bad bacteria from invading.
☆ They produce hormones to help us store lipids better.
☆ 60% of the weight in our feces is bacteria that helped us digest.