unit 2

Question 1

what is matter?

Answer 1

anything that has mass and takes up space

Question 2

what are atoms?

Answer 2

building blocks of matter

Question 3

what are atoms are made up of?

Answer 3

protons, neutrons, and electrons

Question 4

what are elements?

Answer 4

pure substances that cannot be broken down

Question 5

what are the main 4 elements of living things?

Answer 5

hydrogen, oxygen, nitrogen, carbon

Question 6

what are trace elements?

Answer 6

iodine, flourine, iron

Question 7

what are compounds?

Answer 7

2 or more different elements combined

Question 8

what is water?

Answer 8

compound formed by hydrogen and oxygen

Question 9

what are chemical bonds?

Answer 9

force that holds substances together

Question 10

how can atoms become more stable?

Answer 10

by losing or adding electrons from other atoms

Question 11

what is a covalent bond?

Answer 11

share electrons (nonmetal and nonmetal)

Question 12

what is a ionic bond?

Answer 12

transfer electrons (metal and nonmetal)

Question 13

what are the ends of a water molecule?

Answer 13

hydrogen ends are positive and oxygen ends are negative

Question 14

what is the distribution of electrons in water molecule?

Answer 14

unequal, results in oppositely charged regions

Question 15

what is the hydrogen bond?

Answer 15

(hydrogen and lone pair)

Question 16

how much water is in living things?

Answer 16

50-70%

Question 17

how does water benefit chemical reactions?

Answer 17

makes reactions in your body possible

Question 18

what is cohesion?

Answer 18

like molecules attract each other, ex: water molecules stick together to form ocean

Question 19

what is adhesion?

Answer 19

different molecules attract each other, ex: tape sticks to paper

Question 20

what is high surface tension?

Answer 20

water has it, strong “skin” allows things to float on it

Question 21

what is a capillary action?

Answer 21

water moving up a thin tube by itself, ex: meniscus in a graduated cylinder bc water sticks to the glass

Question 22

what is a meniscus?

Answer 22

curve at the surface of a liquid, especially in a graduated cylinder

Question 23

why does ice float on liquid water?

Answer 23

its less dense, ice has more “ordered” hydrogen bonds

Question 24

whats the greatest water density?

Answer 24

4 celsius

Question 25

why is it important for ice to float?

Answer 25

animals are part of habitats that contain ice ex: polar bears, if ice freezes all life underwater will be gone

Question 26

what is a solvent?

Answer 26

liquid that dissolves something, ex: water or something

Question 27

what is a solute?

Answer 27

substance being dissolved, ex: salt

Question 28

how is a solution created?

Answer 28

solvent + solute

Question 29

what are hydration shells?

Answer 29

ionic compounds are surrounded by these clusters of water molecules, allow particles to spread out evenly in the water

Question 30

what is a hydrophilic substance?

Answer 30

substance attracted to water

Question 31

what is a hydrophobic substance?

Answer 31

substance not attracted to water

Question 32

what is the pH of water?

Answer 32

7 bc its neither acidic or basic in its pure state, pH changes when substances are dissolved in it

Question 33

describe high specific heat in water

Answer 33

takes a lot of energy to raise temperature of water, it can take in a lot of heat without it rising much

Question 34

what is evaporative cooling?

Answer 34

evaporation helps cool air, liquid evaporates -> remaining surface cools

Question 35

what does an adequate diet consist of?

Answer 35

fuels, raw materials, essential nutrients

Question 36

what is fuel?

Answer 36

contains proteins, carbs, and fats the body can use to make ATP

Question 37

what are raw materials?

Answer 37

used for biosynthesis, ex: chains of carbon molecules or amino acids

Question 38

what are essential nutrients?

Answer 38

substances that the animal cannot make for itself, ex: vitamins

Question 39

what are organic molecules?

Answer 39

molecules that contain carbon, ex: carbs and proteins

Question 40

what are inorganic molecules?

Answer 40

minerals that don't contain carbon, ex: calcium or iron

Question 41

why does your body need water?

Answer 41

so it can get rid of wastes, keep temperature stable and protect your spinal cord and tissues

Question 42

what are grains?

Answer 42

food group that provide vitamin E, ex: wheat and rice

Question 43

what are vegetables?

Answer 43

food group that provide carbs, vitamins A, C, E, etc.

Question 44

what are fruits?

Answer 44

food group that provide carbs, vitamins, A, C, E, etc.

Question 45

what is dairy?

Answer 45

food group that provide protein, fats, carbs, etc.

Question 46

what is protein?

Answer 46

food group that provide complete proteins, fats, etc.

Question 47

how many calories are in one gram of fat?

Answer 47

9

Question 48

how many calories are in one gram of carbs?

Answer 48

4

Question 49

how many calories are in one gram of protein?

Answer 49

4

Question 50

what are enzymes?

Answer 50

they are catalysts that speed up chemical reactions in the body

Question 51

how does a chemical reaction start?

Answer 51

weak chemical bonds in reactant, get activation energy for molecules to absorb

Question 52

how do enzymes affect activation energy?

Answer 52

they lower the amount required to start a chemical reaction

Question 53

what is an active site?

Answer 53

where enzyme and substract molecules have a chemical reaction

Question 54

are enzymes specific?

Answer 54

yes they usually only work with only 1 substrate, "lock and key"

Question 55

explain the phrase "lock and key"

Answer 55

enzyme and substrate fit exactly into one another, have specific shapes

Question 56

what happens to an enzyme at the end of a chemical reaction?

Answer 56

enzyme is unchanged and can be reused

Question 57

what is denaturation?

Answer 57

changes shape of the enzyme

Question 58

how can temperature affect an enzyme?

Answer 58

increases enzyme activity

Question 59

how can a change in pH affect an enzyme?

Answer 59

leads to change in shape of active site

Question 60

how does the body use enzymes during digestion?

Answer 60

turns nutrients into substances that the digestive tract can absorb, hydrolysis reaction

Question 61

what is a hydrolysis reaction?

Answer 61

the breakdown of compounds with the presence of enzymes and its reaction with water

Question 62

what is the monomer for carbohydrates?

Answer 62

monosaccharide

Question 63

what is the monomer for proteins?

Answer 63

amino acids

Question 64

what is the monomer for nucleic acids?

Answer 64

nucleotides

Question 65

what is the polymer for carbohydrates?

Answer 65

polysaccharide

Question 66

what is the polymer for proteins?

Answer 66

proteins

Question 67

what is the polymer for nucleic acids?

Answer 67

nucleic acids

Question 68

what are the elements contained in carbohydrates?

Answer 68

C, H, O

Question 69

what are the elements contained in protein?

Answer 69

C, H, O, N

Question 70

what are the elements contained in nucleic acids?

Answer 70

C, H, O, N, P

Question 71

what are the elements contained in lipids?

Answer 71

C and H mostly, also has O

Question 72

what is the function of carbohydrates?

Answer 72

source of energy

Question 73

what is the functions of proteins?

Answer 73

energy, repair body and tissues

Question 74

what is the function of proteins?

Answer 74

genetic info

Question 75

what is the function of lipids?

Answer 75

energy storage, steroids, cell membrane

Question 76

what are examples of carbohydrates?

Answer 76

glucose and starch

Question 77

what are examples of proteins?

Answer 77

enzymes and muscle

Question 78

what are examples of nucleic acids?

Answer 78

DNA and RNA

Question 79

lipids example

Answer 79

oil and butter

Question 80

what does it mean for water to be a universal solvent?

Answer 80

it means that it can dissolve many substances