Chemistry Comes Alive (Ch. 2)

Question 1

matter

Answer 1

• a physical substance that occupies space and has mass
• can be solid, liquid, or gas

Question 2

elements

Answer 2

• composes all matter
• can’t be broken down into simpler substances by ordinary chemical methods
• made up of building blocks called atoms

Question 3

atoms

Answer 3

• smallest units of matter
• make up all elements
• non-living
• made up of subatomic particles

Question 4

subatomic particles

Answer 4

• nucleus: central core of an atom
• protons: (+) charged particles
• neutrons: not charged
• electrons: (-) charged particles that orbit the nucleus

Question 5

molecules

Answer 5

since most atoms don’t exist in their free state, they’re usually combined and held together with other atoms by chemical bonds

ex: O₂

Question 6

compounds

Answer 6

molecules can contain multiple elements

ex: H₂O

Question 7

solutions

Answer 7

• homogenous mixtures of components
• can be solid,liquid, or gas
  
  • same composition throughout

Question 8

solvent

Answer 8

substance present in the greatest amount

• acts as dissolving medium
• almost always a liquid
• water is the most common

Question 9

solute

Answer 9

substances present in smaller amounts in a solution

Question 10

water

Answer 10

• most important compound in human body
• makes up approx. 60-80% of body weight
• POLAR MOLECULE
• has (+) & (-) charged ends or poles

Question 11

ions

Answer 11

charged atom that has gained or lost electrons

• also known as electrolyte
• an atom that LOSES electrons becomes positively charged
  
  • positive charged ions are called cations
• an atom that GAINS electrons becomes negatively charged

Question 12

acids

Answer 12

an electrolyte that releases hydrogen ions mixed with water

• proton donor
• sour tasting, react with metals

Question 13

bases (alkaline)

Answer 13

electrolyte that releases hydroxyl ions when added to water

• proton acceptors
• bitter tasting, slippery to the touch

Question 14

pH

Answer 14

measurement of the relative amounts of hydrogen ions in a solution

tells you how acidic or basic a solution is

• pH scale is from 0-14
• neutral: has an equal number of hydrogen & hydroxide ions
• acidic: numbers below 7
• basic: numbers above 7

Question 15

buffers

Answer 15

systems that help to maintain the homeostasis values of pH in the body

• resisting acidic changes by binding molecules to H+
• resisting basic changes by releases H+ molecules

Question 16

organic compounds

Answer 16

compounds that contain carbon

• carbohydrates
• proteins
• lipids
• nucleic acids

Question 17

carbohydrates

Answer 17

building blocks of carbs: carbon, oxygen, hydrogen

function: provide a readily available, easily used source of energy for cells

types of carbohydrates:

• monosaccharides
• disaccharides
• polysaccharides

Question 18

monosaccharides

Answer 18

“one sugar” “simple sugars”

classified by number of carbons they contain

⇢ hexose sugars (6 carbons)

⇢ pentose sugars (5 carbons)

• glucose
• fructose
• galactose
• ribose
• deoxyribose

Question 19

disaccharides

Answer 19

• “double sugar”
• created when 2 monosaccharides join together
• too large to pass through cell membranes of digestive system cells

Question 20

polysaccharides

Answer 20

multiple simple sugars linked together

large, almost insoluble

• makes them ideal for storing materials
• starch is the storage carb formed by PLANTS
• glycogen is the storage carb formed by ANIMALS

Question 21

lipids

Answer 21

“fats”

insoluble in water

building blocks of lipids: carbon, hydrogen, & only a few oxygen atoms

function: good source of energy storage, hormone production & cell structure

1. triglycerides
2. phospholipids
3. steroids

Question 22

triglycerides

Answer 22

found in tissue under the skin & around organs

function: protect & insulate the body, long-term storage of energy

Question 23

phospholipids

Answer 23

modified triglyceride

1 HYDROPHILIC HEAD & 2 HYDROPHOBIC TAILS

function: primary component of cell membrane structure

Question 24

steroids

Answer 24

consist of 4 interlocking hydrocarbon rings

function: produce hormones

most important steroid: CHOLESTEROL

• found in cell membranes
• raw material used for vitamin D synthesis, bile salts
• produces steroid hormones such as estrogen, progesterone, aldosterone, testosterone

Question 25

proteins

Answer 25

function: provide structure in body, acts as enzymes

building blocks of proteins: amino acids

can display different levels of structure depending on # of bonds:

primary secondary, tertiary

Question 26

amino acids

Answer 26

20 different types of amino acids

proteins are long chains of amino acids linked by peptide bonds

Question 27

enzymes

Answer 27

proteins that act as catalysts in chemical reactions

speeds up chemical rxn up to 10Bx faster than the rxn would occur without them

we’d be dead w/o enzymes

Question 28

nucleic acids

Answer 28

largest organic molecules/compounds in the human body

types of nucleic acids:

RNA⇢ Ribonucleic Acid

DNA ⇢Deoxyribonucleic Acid

ATP ⇢Adenosine Triphosphate

Question 29

Nucleotides

Answer 29

building blocks of nucleic acids

DNA ⇢ Adenine, Thymine, Cytosine, Guanine

RNA ⇢ Adenine, Uracil, Cytosine, Guanine

Question 30

ATP

Answer 30

Adenosine Triphosphate

ATP = ENERGY

function: transfers energy for cell activities

• very important nucleic acid for humans
• “energy currency” of all living systems