Chapter 2 Flashcards

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1
Q

Life

A

ability to replicate and by the presence of some sort of metabolic activity

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2
Q

Biodiversity

A

variety and variability among all genes, species, and ecosystems

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3
Q

Element

A

substance that can’t be broken down into any other substances

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4
Q

Everything (matter) is made up of:

A

atoms

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5
Q

atom

A

a particle of matter that can’t be further subdivided without losing essential properties

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6
Q

what are the three parts of an atom?

A

nucleus, and three other parts: electrons, protons, and neutrons

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7
Q

mass

A

The amount of matter in a particle

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8
Q

electrons weight almost:

A

nothing; they weight 1/20th of one percent

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9
Q

atomic mass

A

combined mass of all of the atom’s protons and neutrons

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10
Q

Particles that have the same charge ___ each other

A

repel

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11
Q

Particles with opposite charges are _____ to each other

A

attracted

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12
Q

How can we tell elements apart?

A

by their atomic number, which means how many PROTONS are in the nucleus

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13
Q

Elements differ in their number of ____

A

protons

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14
Q

element symbol

A

abbreviation of the element’s name

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15
Q

The mass of an atom is often about double the element’s atomic number

A

example:
Oxygen mass: 15.99
atomic number: 8

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16
Q

Isotopes

A

Atoms with the same atomic number (number of protons), but different numbers of neutrons

(extra neutrons or fewer neutrons than the number of protons)

(same protons, different neutrons)

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17
Q

in isotopes, does the charge change? Why?

A

-no because neutrons don’t have a charge

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18
Q

Does the atom’s mass change in isotopes?

A

yes, with the loss or addition of another particle in the nucleus

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19
Q

Radioactive

A

elements/isotopes having an unstable nucleus, breaking down spontaneously, releasing tiny, high-speed particles that carry a lot of energy.

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20
Q

Radioactive atoms turn out to be useful in determining what?

A

the age of fossils

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21
Q

Of all the elements found on earth, how many are found in your body?

A

25

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22
Q

The “Big 4” elements consist of:

A

oxygen, carbon, nitrogen, hydrogen

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23
Q

The “Big 4” make up how much of our body mass?

A

more than 96%

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24
Q

ions

A

electrically charged atoms

-number of protons are same, but number of electrons are different

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25
Q

ions have a ___/___ bond

A

positive/negative

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26
Q

extra electrons mean __ charge and

extra protons mean __ charge

A

negative; positive

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27
Q

An atom’s ____ determine how and whether the atom will bond with other atoms

A

electons

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28
Q

The first electron shell holds ___ electrons, and is ___ to the nucleus

A

2; closest

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29
Q

the second electron shell is ___ away from the nucleus, and can hold up to ___ electrons

A

farther; 8

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30
Q

how many shells can there be total?

A

up to 7

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31
Q

If an element doesn’t have eight atoms, how can they get some?

A

through bonding

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32
Q

Groups of atoms are held together by what?

A

bonds/molecules

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33
Q

Covalent bonds

A

STRONG bonds that form when atoms share electons

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34
Q

Double bonds

A

The sharing of two pairs of electrons between two atoms

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35
Q

Covalent bonds ..

A

SHARE electrons

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36
Q

Ionic bonds…

A

TRANSFER electrons

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37
Q

Ionic bond

A

transferring electrons (now called ions) –oppositely charged ions attract each other and form compound

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38
Q

Hydrogen bonds

A

link multi-atom MOLECULES togehter

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39
Q

Hydrogen bonds are important for bonding..

A

molecules together

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40
Q

Ionic and covalent bonds link ___ together

A

atoms

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41
Q

hydrogen bonds

A

link multiatom molecules together

-formed between a H in one molecule and another molecule, often O or N

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42
Q

Hydrogen bonds are formed between

A

the slightly positively charged hydrogen atoms of one molecule and the slightly negatively charged oxygen atom of another

-usually a polar atom and a hydrogen atom

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43
Q

ionic bonds

A

oppositely charged atoms attract eachother to form a compound, TAKEN not shared (covalent)

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44
Q

electrons determine what?

A

HOW nd WHETHER the atom will bond with others

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45
Q

Polar

A

one side is positive, and one is negative

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46
Q

what are polar molecules attracted to?

A

other polar molecules

-ex: water is the most famous one

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47
Q

are hydrogen bonds strong or weak?

A

weak

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48
Q

Ionic bonds form _______, while covalent bonds form ________

A

compounds; molecules

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49
Q

Because of their unequally shared electrons, water molecules are ..

A

polar

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50
Q

hydrogen bonds make water

A

cohesive

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51
Q

all life on earth depends on

A

water

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52
Q

cohesion allows tall trees to exist because

A

hydrogen bonds allow water molecules to pull up other molecules

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53
Q

water has four unusual properties that are critical, what are they?

A

cohesion, large heat capacity, low density as a solid, good solvent

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54
Q

When it’s a hot beach day, why is the sand hot but the water isn’t?

A

hydrogen bonds; hydrogen bonds help resist heating

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55
Q

cohesion

A

attraction between two like things

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56
Q

adhesion

A

attraction between two different things

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57
Q

heat capacity is like the ability to absorb heat well without reflecting it

A

n/a

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58
Q

low density as a solid

A

ice floats in water

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59
Q

good solvent

A

Water pries apart ionic bonds, dissolving ionic compounds.

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60
Q

What allows us to remain at a stable temperature despite the weather outisde?

A

heat capacity

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61
Q

PH Scale: below 7

A

acidic; more h+ (Less OH-)

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62
Q

above 7

A

basic; fless h+ (more OH-)

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63
Q

the lower the ___ the greater the ____ on the ph scale

A

lower;acidity

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64
Q

a decrease of 1 on the pH scale represents a ____-fold increase in the hydrogen ion concentration

A

ten

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65
Q

ph scale

A

a way of referring to the acidic, basic, or chemically neutral quality of a fluid.

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66
Q

buffers

A

chemicals that can quickly absorb excess H+ ions to keep a solution from becoming too acidic, and they can quickly release H+ ions to counteract any increases in OH− concentration.

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67
Q

when blood ph levels become too acidic, a buffer chemical absorbs excess what?

A

H+ ions

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68
Q

when a blood ph level becomes too basic..

A

a buffer chemical rleases h+ ions

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69
Q

The pH scale is a direct measure of:

A

the concentration of hydrogen ions in a solution.

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70
Q

The tendency of water molecules to stick together is called:

A

cohesion

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71
Q

A chemical compound that releases H+ into a solution is called:

A

An acid

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72
Q

buffers help PH ..

A

get back to normal

73
Q

macromolecules

A

a large molecule made up from smaller building blocks or subunits.:

74
Q

what are the four types of macromolecules

A

lipids, carbohydrates, proteins, and nucleic acids

75
Q

carbohydrates

A

molecules that contain carbon, hydrogen, and oxygen: they are the primary fuel for running all of the cellular machinery and also form much of the structure of cells in all life forms.

-primary fuel for organisms

76
Q

carbohydrates are classified by:

A

size

77
Q

monosaccharides

A

simplest macromolecule

ex: glucose and fructose

78
Q

Why do carbohydrate molecules function so well as fuels for the body?

A

Carbohydrates have many carbon-hydrogen bonds that store a great deal of energy. These bonds are easily broken, and the energy can be captured by organisms.

79
Q

Carbs are the primary fuel for running all cellular machinery and also form much of the structure of cells in all life forms

A

n/a

80
Q

glucose provides energy for..

A

the body’s cells

81
Q

carbohydrates ultimately convert into what

A

glucose

82
Q

glucose can be stored as what in the muscles and liver for later use, or can be converted to what

A

gylcogen; fat

83
Q

what are the three uses of glycogen?

A

1: fuel for cellular activity
2: stored temporarily as glycogen
3: converted to fat

84
Q

glycogen is hydro..

A

philic

85
Q

What are the three basic tupes of carbohydrates?

A

monosaccharides, disaccharides, polysaccharides

86
Q

monosaccharides are

A

simple sugars
ex
fruit, milk, cake, candy

87
Q

disaccharides

A

two sugars joined together

88
Q

polysaccharides

A

many simple sugars joined together
ex
starch, glycogen,cellulose(structural support for plants)

89
Q

energy received from braking down carbohydrates

A

n/a

90
Q

some carbohydrates are stronger or weaker than others?

A

greater than

91
Q

glucose that isn’t used turns into what?

A

fat

92
Q

To use sucrose, the body must first break the bond linking

A

glucose and fructose

93
Q

starch

A

A complex polysaccharide carbohydrate consisting of a large number of monosaccharides linked in line;
;the primary form of energy storage is a complex carbohydrate

94
Q

Starch and glucose are both carbohydrates. So why does starch fail to provide you the quick burst of energy that glucose can provide?

A

Starch is a more complex carbohydrate, consisting of hundreds or more sugar molecules covalently linked together. You cannot directly use starch; your body must first break the covalent bonds connecting these sugar molecules, and this takes time.

95
Q

which carbohydrates are not digestable by humans?

A

chitin and cellulose

96
Q

chitin function

A

orms the rigid outer skeleton of most insects

97
Q

cellulose function

A

forms a huge variety of plant structures that are visible all around us

98
Q

if humans can’t digest cellulose, why is it still so important for our diet?

A

Dietary cellulose is called fiber, and it helps move materials through the digestive system.

99
Q

What is “carbo-loading”?

A

It is a method by which athletes can increase the usual amount of glycogen that is stored in their muscles and liver, increasing the amount of fuel available for extended exertion and delaying the onset of fatigue during an endurance event.

100
Q

lipids

A

insoluble in water and greasy to the touch. Lipids are important in energy storage and insulation (fats), membrane formation (phospholipids), and regulating growth and development

101
Q

lipids are primarily made up of what?

A

are made primarily from atoms of carbon, hydrogen, and oxygen, but the atoms are in different proportions

102
Q

are lipids hydrophobic or hyrophilic?

A

hydroPHOBIC

103
Q

lipids are used as an ___ source

A

energy

104
Q

why aren’t lipids soluable in water?

A

have long chains consisting only of carbon and hydrogen atoms

105
Q

chains of carbon and hydrogen atoms are polar or nonpolar?

A

nonpolar

106
Q

What are the three main types of lipids? What function do they serve in the body?

A

The three main types of lipids are:

  • fats: store energy for long periods of time and insulate the body.
  • sterols: such as cholesterol, regulate growth and development.
  • phospholipids: form the membranes that enclose cells.
107
Q

lipid function

A

long term energy storage, insulation, mebrane formation, and as hormones

108
Q

are lipids soluble in water?

A

no, greasy to touch

109
Q

fatty acid

A

A long hydrocarbon (a chain of carbon-hydrogen molecules; form the tail region of triglyceride fat molecules

110
Q

hydrocarbon

A

a chain of carbon atoms, often a dozen or more, linked together and with one or two hydrogen atoms attached to each carbon atom.

111
Q

triglycerides have:

A

glycerol heads and fatty acid tails

112
Q

saturated fats

A

A fat in which each carbon in the hydrocarbon chain forming the tail region of the molecule is bound to two hydrogen atoms; saturated fats are solid at room temperature.

113
Q

unsaturated fats

A

some of the carbon atoms are bound to only a single hydrogen (and are connected to each other by a double bond

114
Q

fake fat

A

olestra

115
Q

fats

A

. Triglycerides that are solid at room temperature

116
Q

oils

A

liquid at room temperature

117
Q

three types of lipids

A

fats, sterols, phospholipids

118
Q

structures make lipids polar, which means..

A

hydrophobic

119
Q

sterol

A

lipid important in regulating growth and development.

120
Q

cholesterol, estrogen, and testosterone are all types of which macromolecule?

A

lipids

121
Q

phospholipids

A

major component of the membrane that surrounds the contents of a cell and controls the flow of chemicals into and out of the cell

122
Q

phospholipid vs fat in structure

A

contain a phosphorus atom (hence phospholipids) and they have two fatty acid chains rather than thre

123
Q

An unsaturated fatty acid is one in which:

A

carbon-carbon double bonds are present in the hydrocarbon chain

124
Q

Saturated fatty acids have _________________ than unsaturated fatty acids, which is why they exist as a ____________ at room temperature.

A

fewer double bonds; solid

125
Q

Unsaturated fatty acid chains in membrane phospholipids help to maintain fluidity because:

A

they are less likely to pack tightly at lower temperatures, and they have kinks induced by extra carbon-carbon double bonds

126
Q

In a phospholipid, the head is _____, and the fatty acid is _____.

A. hydrophilic, hydrophilic

A

hydrophilic; hydrophobic

127
Q

proteins are like bodybuilding macromolecules

A

n/a

128
Q

proteins

A

constructed of unique combinations of 20 amino acids that result in unique structures and chemical behavior

129
Q

enzyme

A

t initiates and accelerates a chemical reaction in a living organism

130
Q

amino acid

A

One of 20 molecules built of an amino group, a carboxyl group, and a unique side chain. Proteins are constructed of combinations of amino acids linked together.

131
Q

carboxyl group

A

carbon atom bonded to two oxygen atoms (to one by a single bond and to the other by a double bond).

132
Q

amino group

A

nitrogen atom bonded to hydrogen atoms (usually two or three).

133
Q

amino acid structure

A

Amino acids are made up of a central carbon atom attached to a hydrogen atom, an amino group, a carboxyl group, and a side chain.

134
Q

list six different functions of proteins

A

structural, protective, regulatory, contractile, transport, and enzyme roles for proteins

135
Q

strucgtural protein function

A

s form hair, fingernails, feathers, and other structures in organisms

136
Q

protective protein function

A

elp fight invading microorganisms

137
Q

regulatory proteins function

A

ex: hormones,

control cell activity.

138
Q

contractile proteins

A

allow muscles to contract and the heart to pump

139
Q

trasnport proteins ex

A

carry molecules such as oxygen around the body.

140
Q

protective proteins

A

help clot blood

141
Q

regulatory proteins control

A

cell activity

142
Q

contractile proteins help sperm

A

swim

143
Q

transport proteins carry molecules

A

around the body

144
Q

proteins are built up of amino acids

A

polypeptides

145
Q

how many different kinds of amino acids are there

A

twenty

146
Q

amino acids all have what

A

amino acids, carboxyl groups (same backbone) but have different SIDE CHAINS

147
Q

Polypeptide

A

complex polymer built up of amino acids

148
Q

If all twenty amino acids are necessary for proteins, then why are only about half of them called “essential”?

A

The essential amino acids are the ones that human cannot manufacture, so it is essential that they are supplied in our diet.

149
Q

peptide bond

A

amino group of one amino acid is bonded to the carboxyl group of another.

150
Q

secondary structure

A

The corkscrew-like twists or folds of a protein that are held in place by hydrogen bonds between amino acids in the polypeptide chain

151
Q

tertiary structure

A

complex three-dimensional shape of a protein formed by multiple twists of its secondary structure as amino acids come together to form hydrogen bonds or covalent sulfur-sulfur bonds

152
Q

quarternary structure

A

two or more polypeptide chains are held together by hydrogen bonds and other non-peptide bonds between amino acids in the different chains.

153
Q

The overall shape of a protein molecule determines its

A

function (how it behaves and the other molecules it interacts)

154
Q

For proteins to function properly, they must retain their

A

3d shape

155
Q

denaturation

A

lose function when folding

156
Q

active site

A

The part of an enzyme to which reactants (or substrates) bind and undergo a chemical reaction.

157
Q

substrate

A

molecule on which an enzyme acts. The active site on the enzyme binds to the substrate, initiating a chemical reaction

158
Q

each enzyme has an active site that is perfect for its substance

A

n/a

159
Q

like a key in a lock, what fits in the active site?

A

lactose; this bond between teh simple sugar is broken

160
Q

the two simple sugars making up lactose are then released. which two sugars?

A

glucose and galactose

161
Q

activation energy

A

the little push in order to initiate a reaction in chemical reactions

162
Q

how do enzymes act as catalysts?

A

lowering the activation energy

163
Q

Only the substrate molecules are of the correct ___ and ____ to fit into the active-site groove

A

size and shape

164
Q

Once a substrate molecule is bound to the active site, a reaction

A

can take place, and does so quickly

165
Q

The chemical reactions that occur in organisms can either /or/ energy.

A

release or consume

166
Q

enzymes bind to the substrate at the active site, positioning the atoms in the active site in a manner that weakens the bonds in the substrate, what does this do?

A

lowering the activation energy necessary for the chemical reaction to occur

167
Q

The rate at which an enzyme catalyzes a reaction is influenced by several chemical and physical factors.

A
Enzyme and substrate concentration
More stuff, more likely to run into each other
Temperature (optimal)
Gets molecules moving 
pH
Have an optimal pH
Presence of inhibitors or activators
168
Q

For a given amount of substrate, an increase in the amount of enzyme ____the rate at which the reaction occurs

A

increases

169
Q

temperature: reaction rates will increase until optimum, and if there already, it’ll denature from that point

A

n/a

170
Q

Interactions with PH

A

disrupt enzyme function (and sometimes structure) and decrease reaction rates.

171
Q

One of the most common ways that cells can speed up or slow down their metabolic pathways is through

A

the binding of other chemicals to enzymes. This binding can alter enzyme shape in a way that increases or decreases the enzyme’s activity.

172
Q

inhibitors

A

reduce enzyme activity and come in two types

173
Q

competitive inhibitors

A

bind to the active site, blocking substrate molecules from the site and thus from taking part in the reaction

174
Q

noncompetitive inhibitors

A

do not compete for the active site but, rather, bind to another part of the enzyme, altering its shape in a way that changes the structure of the active site, thus reducing or blocking its ability to bind with substrate.

175
Q

Enzyme activity is influenced by

A

physical factors: temperature & pH
chemical factors: enzyme & substrate concentrations
inhibitors & activators

176
Q

activator

A

A chemical within a cell that binds to an enzyme, altering the enzyme’s shape or structure in a way that causes the enzyme to catalyze a reaction.

177
Q

Proteins are an essential component of a healthy diet for humans (and other animals). Their most common purpose is to serve as:

A

raw material for growth

178
Q

dietary proteins are considered complete when

A

are considered “complete” only if they contain the eight essential amino acids required by humans.