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Biomolecules
The structures Of Life.
Macromolecules• Monomers= single units• Polymer= many
monomers bound together
• Monomers, the single units, are polymerized (joined together) to form a polymer
4 Biomolecules in living things
Four groups of organic compounds found in living things are:
• carbohydrates• lipids• nucleic acids• proteins
I. Carbohydrates
• Carbohydrates • organic compound made of C, H, & O.
Carbon, hydrogen, and oxygen are usually in the ratio of 1:2:1
C6H12O6
Function of Carbohydrates
• Living things use carbohydrates as their main source of energy
• Plants and some animals use them as structural support
Examples of Carbohydrates
• Sugars– Monosaccharides– Disaccharides– Polysaccharides
3 types of sugars:
• Monosaccharides-simple sugars ( 1 sugar
carbohydrate)• Glucose &
Fructose
• Disaccharides– sucrose & Lactose ( 2
sugars linked together)
• Polysaccharides– many simple sugars
linked together
Glucose
Sucrose
Fig. 5-2a
Dehydration removes a watermolecule, forming a new bond
Short polymer Unlinked monomer
Longer polymer
Dehydration reaction in the synthesis of a polymer
HO
HO
HO
H2O
H
HH
4321
1 2 3
(a)
• A disaccharide is formed when a dehydration reaction joins two monosaccharides
• This covalent bond is called a glycosidic linkage
Animation: DisaccharidesAnimation: Disaccharides
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Fig. 5-2b
Hydrolysis adds a watermolecule, breaking a bond
Hydrolysis of a polymer
HO
HO HO
H2O
H
H
H321
1 2 3 4
(b)
Fig. 5-3
Dihydroxyacetone
Ribulose
Ket
ose
sA
ldo
ses
Fructose
Glyceraldehyde
Ribose
Glucose Galactose
Hexoses (C6H12O6)Pentoses (C5H10O5)Trioses (C3H6O3)
A monosaccharide is a
• A. carbohydrate• B. lipid• C. nucleic acid• D. protein
• A. carbohydrate
How many sugars make up a disaccharide?
• A. one• B. two• C. three• D. many
• B. two
Sugars, starches, and cellulose are all examples of which group of biomolecules?
• A. proteins• B. amino acids• C. lipids• D. carbohydrates
• D. carbohydrates
Storage Polysaccharides
• Starch, a storage polysaccharide of plants, consists entirely of glucose monomers
• Plants store surplus starch as granules within chloroplasts and other plastids
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Fig. 5-6
(b) Glycogen: an animal polysaccharide
Starch
GlycogenAmylose
Chloroplast
(a) Starch: a plant polysaccharide
Amylopectin
Mitochondria Glycogen granules
0.5 µm
1 µm
• Glycogen is a storage polysaccharide in animals• Humans and other vertebrates store glycogen
mainly in liver and muscle cells
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• Chitin, another structural polysaccharide, is found in the exoskeleton of arthropods
• Chitin also provides structural support for the cell walls of many fungi
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Fig. 5-10
The structureof the chitinmonomer.
(a) (b) (c)Chitin forms theexoskeleton ofarthropods.
Chitin is used to makea strong and flexiblesurgical thread.
Lipids• Fats, oils, waxes, steroids (examples)• Are made mostly of carbon, hydrogen, and
oxygen• Are not soluble in water (they are nonpolar)• Hydrogen : oxygen ratio is greater than 2:1
Functions of Lipids
• Used to store energy• Important part of biological membranes
Fig. 5-14
Hydrophilichead
Hydrophobictail WATER
WATER
Steroids
• Steroids are lipids characterized by a carbon skeleton consisting of four fused rings
• Cholesterol, an important steroid, is a component in animal cell membranes
• Although cholesterol is essential in animals, high levels in the blood may contribute to cardiovascular disease
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Fig. 5-15
2. Saturated Lipids : Solid fats, animals
3. Unsaturated Lipids: Oils, plants
Fig. 5-12a
(a) Saturated fat
Structuralformula of asaturated fatmolecule
Stearic acid, asaturated fattyacid
Fig. 5-12b
(b) Unsaturated fat
Structural formulaof an unsaturatedfat molecule
Oleic acid, anunsaturatedfatty acid
cis doublebond causesbending
• Hydrogenation is the process of converting unsaturated fats to saturated fats by adding hydrogen
• Hydrogenating vegetable oils also creates unsaturated fats with trans double bonds
• These trans fats may contribute more than saturated fats to cardiovascular disease
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Q. What is the difference between saturated and unsaturated fatty acids?
A. Unsaturated fatty acids have a carbon = carbon double bond.
Q. What is the difference between saturated and unsaturated fatty acids?
C10H20O2
C10H18O2
Fig. 5-11a
Fatty acid(palmitic acid)
(a) Dehydration reaction in the synthesis of a fat
Glycerol
Fig. 5-11b
(b) Fat molecule (triacylglycerol)
Ester linkage
• Biomolecules composed mainly of carbon, hydrogen, and oxygen in a ratio of 2 hydrogen for every 1 oxygen would be a ___________.
a. Carbohydrateb.Proteinsc. Amino acidsd.Nucleic acids
• A. carbohydrate
• This atom is a major part of biomolecules, or organic molecules.A. helium (He)
B. fluorine (F) C. carbon (C) D. sodium (Na)
• C. carbon
The structural component of plant cell wallsa. celluloseb.Starchc. proteinsd.Glycogen
• C. cellulose
• Which of the following is not a polymer? a. Starchb.Glucosec. Cellulosed.chitin
• A. cellulose
• On food packages, to what does the term "insoluble fiber" refer?
a. Polypeptideb.Chitinc. Starchd.Cellulose
• D. cellulose
• A molecule with the chemical formula C6H12O6 is probably a
a. Lipidb.Proteinc. Carbohydrated.None of the above
• C. carbohydrate
• Cell membranes are made ofA. many lipids called phospholipids
B. long chains of sugar C. amino acids and water
• A. many lipids called phospholipids
Which type of fat is healthy?a. Saturated fatsb.Unsaturated fats
• B . Unsaturated fats
Proteins
• Organic compound made up of: CarbonHydrogenOxygenNitrogen
3. Proteins are essential to living things:Proteins are needed to build & maintain cells, digest food, growth, insulin, antibodies for immunity, transmit heredity, movement.
4. Examples of Proteins:◊ Hemoglobin – carries O2
◊ Actin – muscle contraction
◊ Saliva (Enzyme) – breakdown Carbohydrates.
◊ Lactase (Enzyme) – digest lactose sugar
Proteins
Polymers of amino acids
Amino Acids are linked together to make proteins.
Amino acids are the monomers and proteins are the polymers.
Amino acids
• There are 20 different amino acids that are incorporated into proteins.
• All amino acids have an Amino Group (NH2), a Carboxyl group (COOH), and an R-Group (unique side chain that distinguishes that amino acid.
Amino Acid Monomers
• Amino acids differ in their properties due to differing side chains, called R groups
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Fig. 5-UN1
Aminogroup
Carboxylgroup
carbon
Fig. 5-17Nonpolar
Glycine(Gly or G)
Alanine(Ala or A)
Valine(Val or V)
Leucine(Leu or L)
Isoleucine(Ile or )
Methionine(Met or M)
Phenylalanine(Phe or F)
Trypotphan(Trp or W)
Proline(Pro or P)
Polar
Serine(Ser or S)
Threonine(Thr or T)
Cysteine(Cys or C)
Tyrosine(Tyr or Y)
Asparagine(Asn or N)
Glutamine(Gln or Q)
Electricallycharged
Acidic Basic
Aspartic acid(Asp or D)
Glutamic acid(Glu or E)
Lysine(Lys or K)
Arginine(Arg or R)
Histidine(His or H)
• The sequence of amino acids determines a protein’s three-dimensional structure
• A protein’s structure determines its function
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Four Levels of Protein Structure
• The primary structure of a protein is its unique sequence of amino acids
• Secondary structure, found in most proteins, consists of coils and folds in the polypeptide chain
• Tertiary structure is determined by interactions among various side chains (R groups)
• Quaternary structure results when a protein consists of multiple polypeptide chains
Animation: Protein Structure IntroductionAnimation: Protein Structure Introduction
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Fig. 5-21
PrimaryStructure
SecondaryStructure
TertiaryStructure
pleated sheet
Examples ofamino acidsubunits
+H3N Amino end
helix
QuaternaryStructure
Fig. 5-21a
Amino acidsubunits
+H3N Amino end
25
20
15
10
5
1
Primary Structure
Fig. 5-21d
Abdominal glands of thespider secrete silk fibers
made of a structural proteincontaining pleated sheets.
The radiating strands, madeof dry silk fibers, maintain
the shape of the web.
The spiral strands (capturestrands) are elastic, stretching
in response to wind, rain,and the touch of insects.
Fig. 5-21f
Polypeptidebackbone
Hydrophobicinteractions andvan der Waalsinteractions
Disulfide bridge
Ionic bond
Hydrogenbond
Sickle-Cell Disease: A Change in Primary Structure
• A slight change in primary structure can affect a protein’s structure and ability to function
• Sickle-cell disease, an inherited blood disorder, results from a single amino acid substitution in the protein hemoglobin
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Fig. 5-22c
Normal red bloodcells are full ofindividualhemoglobinmolecules, each carrying oxygen.
Fibers of abnormalhemoglobin deformred blood cell intosickle shape.
10 µm 10 µm
What Determines Protein Structure?
• In addition to primary structure, physical and chemical conditions can affect structure
• Alterations in pH, salt concentration, temperature, or other environmental factors can cause a protein to unravel
• This loss of a protein’s native structure is called denaturation
• A denatured protein is biologically inactive
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5. All chemical reactions that take place in the body are controlled by enzymes and all enzymes are proteins.
Which of the following is NOT a function of proteins?
• A. store and transmit heredity in the form of a chemical code
• B. Help to fight disease (antibodies for immunity)
• C. Control the rate of reactions and regulate cell processes
• D. Build tissues such as bone and muscle
Answer
• A. store and transmit heredity in the form of a chemical code
___ link together to make up proteins.
• A. sugars• B. lipids• C. amino acids• D. nucleic acids
Answer
• C. amino acids
If you were trying to identify a structural formula as protein, what would you look for?
• A. less than 2:1• B. greater than 2:1• C. 2:1• D. an NH2 & -COOH group, which are known as
an amino group and a carboxyl group
• D. an NH2 & -COOH group, which are known as an amino group and a carboxyl group
D. Nucleic Acids
• Function- transmits and stores genetic information
• Composed of C, H, O, N & P (Phosphorous).
Structure of a nucleotide, the monomer of a nucleic acid
2 types of Nucleic acids
• 1) Deoxyribonucleic acid– Contains the sugar deoxyribose– Double stranded
• 2)Ribonucleic acid– Contains the sugar ribose– Single stranded
Fig. 5-26-1
mRNA
Synthesis ofmRNA in thenucleus
DNA
NUCLEUS
CYTOPLASM
1
The Structure of Nucleic Acids
• Nucleic acids are polymers called polynucleotides
• Each polynucleotide is made of monomers called nucleotides
• Each nucleotide consists of a nitrogenous base, a pentose sugar, and a phosphate group
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Fig. 5-27
5 end
Nucleoside
Nitrogenousbase
Phosphategroup Sugar
(pentose)
(b) Nucleotide
(a) Polynucleotide, or nucleic acid
3 end
3C
3C
5C
5C
Nitrogenous bases
Pyrimidines
Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA)
Purines
Adenine (A) Guanine (G)
Sugars
Deoxyribose (in DNA) Ribose (in RNA)
(c) Nucleoside components: sugars
Fig. 5-27c-1
(c) Nucleoside components: nitrogenous bases
Purines
Guanine (G)Adenine (A)
Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA)
Nitrogenous bases
Pyrimidines
E. Testing summary for Biomolecules1. Benedict’s solution = yellow or
reddish-orange for simple sugars.
2. Iodine solution = black for starch (complex carbohydrate)
3. Biuret solution = violet for protein.
4. Sudan IV solution = red for lipids
5. Lipids = clear or translucent spot on brown paper.
Question
• Which biomolecule is composed of carbon, hydrogen, oxygen, nitrogen, and phosphorous. It also stores and transmits genetic information?
a. Carbohydratesb.Proteinsc. Lipidsd.Nucleic acids
Answer
• D. nucleic acids
DNA & RNA are two types of ____
• A. carbohydrates• B. nucleic acids• C. proteins• D. lipids
• B. nucleic acids
All chemical reactions that take place in the body are controlled by
• A. enzymes• B. lipids• C. sugars• D. RNA
Answer
• A. enzymes
Which group of biomolecules do enzymes belong to?
a. Lipidsb. Carbohydratesc. Proteinsd. Nucleic acids
Answer
• C. proteins
Which biomolecule does deoxyribonucleic acid belong to?• A. carbohydrates • B. lipids • C. proteins • D. nucleic acids
• D. nucleic acid
Which monomers contain N?• A. carbohydrates • B. lipids • C. proteins • D. nucleic acids
• C & D- proteins, nucleic acids
Some of these are inorganic • A. carbohydrates • B. lipids • C. proteins • D. none
• D. none
Contain carbon, hydrogen and oxygen• A. carbohydrates • B. lipids • C. proteins • D. nucleic acids • E. all of the above
• E. all of the above
Contain all the elements C,H, O, N, and P • A. carbohydrates • B. nucleic acids • C. proteins • D. lipids • E. none
• B. nucleic acids
Examples are glucose, sucrose, and maltose • A. carbohydrates • B. lipids • C. proteins • D. nucleic acid • E. none
• A. carbohydrate
Fats, oils, and waxes • A. carbohydrates • B. lipids • C. proteins • D. nucleic acids • E. none
• B. lipids
Monomers made of sugar, N-base, and phosphate • A. carbohydrates • B. lipids • C. nucleic acid • D. protein• E. none
• C. nucleic acid
Enzymes are• A. carbohydrates • B. proteins • C. lipids• D. nucleic acids • E. none
• B. proteins
THEEND