Macromolecules

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Macromolecules

• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids

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1. Carbohydraytes

• Are organic compounds made of sugars and their
  monomers.
• Monomers are called monosaccharides.
• 2 monomers are disaccharides
• Polymers are polysaccharides

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monosaccharides

• C, H, and O occur in a ratio that is ALWAYS
• Are the major source energy for all cells.

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monosaccharides

• Aldehydes-
• Ketones-

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Figure 5.3 The structure and classification of
some monosaccharides
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monosaccharides

• Location/spatial arrangement of functional groups
  are important!
• Isomers

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monosaccharides

• Carbohydrates can be linear, but form rings in
  aqueous solutions.

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Disaccharides

• contain two monosaccharides.
• formed through the process of
• Monosaccharide monosaccharide ? Disaccharide

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Figure 5.5 Examples of disaccharide synthesis
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Polysaccharides

• Macromolecules that are polymers of a few hundred
  or thousand monosaccharides.
• Important in
• 1.
• 2.

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Polysaccharides Energy Storage

• starch

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Polysaccharides Energy - Starch

• Starch is the energy found in plants.
• Made entirely of
• Two common forms are amylose (unbranched) and
  amylopectin (branched).

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Polysaccharides Energy - Glycogen

• Glycogen is how store their energy.
• Made entirely of glucose and highly branched.
• Where do animals store their glycogen reserves?

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Polysaccharides Structural

• Cellulose is found in
• Made entirely of glucose, but differs from starch
  because of where the branching is.
• Can you digest cellulose?
• What can?

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Figure 5.8 The arrangement of cellulose in plant
cell walls
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Figure 5.6 Storage polysaccharides
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Figure 5.7b,c Starch and cellulose structures 
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• Chitin is found in the exoskeleton of arthropods
  and the walls of some fungi.
• Chitins monomer is an amino sugar.

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Figure 5.9 Chitin, a structural polysaccharide
exoskeleton and surgical thread
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Macromolecules 2. Lipids

• Diverse group of molecules that are non-polar.
  There are three major groups
• 1. Fats
• 2.
• 3.

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Lipids 1. Fats

• glycerol attached to 3 fatty acid chains.
• Glycerol is a
• Fatty acids are hydrocarbons with a carboxyl
  group at one end.
• Hydrocarbon tail is extremely hydrophobic.

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Fats

• Hydrocarbons have a long Carbon skeleton with an
  even number of Cs (usually 16 or 18).
• Fats are built by condensation synthesis, linking
  3 fatty acid tails to a single glycerol molecule.

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• This linking results in a covalent bond called an
  
• Entire macromolecule (glycerol 3 fatty acids)
  is called a

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Lipids

• Fatty acid (FA) chains in a triglyceride may all
  be the same, or can all be different.
• Variation comes from
• 1. Different FA chains
• 2.
• 3. Number location of double bonds
• in a chain.

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Lipids

• Fats may be
• 1.
• 2.
• What are fats saturated with?

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Lipids Saturated Fats

• No C to C
• C skeleton is bonded to the maximum number of Hs
  (saturated w/Hs).
• Usually a solid at room temperature.
• Most
• Ex

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Lipids Unsaturated Fats

• Are not saturated with H, because there are C C
  double bonds present.
• The chain bends at each C C, so molecules can
  not pack tight together.
• Are at room temperature.
• Most
• Corn oil, peanut oil, olive oil

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• In many commercially produced foods, unsaturated
  fats are artificially hydrogenated to prevent
  them from spreading out into an oil.
• Ex

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Figure 5.11 Examples of saturated and
unsaturated fats and fatty acids 
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Lipids The functions of Fats

• Energy storage- one gram of fat stores 2x the
  energy of a carbohydrate.
• More compact fuel
• Cushions
• Insulation
• Fat

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Lipids 2. Phospholipids

• Compound with a backbone of glycerol, bonded to 2
  FA chains.
• Replacing the 3rd FA chain is instead a phosphate
  group.
• Attached to the phosphate group is another small
  chemical group.

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Figure 5.12 The structure of a phospholipid
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Figure 5.13 Two structures formed by
self-assembly of phospholipids in aqueous
environments   
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Lipids 3. Steroids

• Steroids have four fused carbon rings with
  various f(x)al groups.
• Some hormones are steroids.
• Cholesterol is an important steroid because
• 1. it is the precursor
• 2. Found in animal

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Figure 5.14 Cholesterol, a steroid    
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Figure 4.8 A comparison of functional groups of
female (estradiol) and male (testosterone) sex
hormones
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Figure 46.10 Ovulation
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Figure 46.13b Oogenesis
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Figure 46.9x Ovary (left) and follicle (right)
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Figure 46.15 The reproductive cycle of the human
female
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FSH

• Follicle stimulating hormone
• It is the main hormone involved in producing
  mature eggs.

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LH

• In both sexes, LH stimulates secretion of sex
  steroids from the gonads.

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GnRH

• gonadotropin-releasing hormone
• Made by the hypothalamus.
• Signals the pituitary to make LH and FSH
• Works as a negative feedback loop

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Figure 46.14 Hormonal control of the testes
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Progesterone

• maintains the uterine lining during pregnancy

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Figure 46.16 Formation of the zygote and early
postfertilization events
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Figure 46.19 Hormonal induction of labor
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Figure 46.11x Spermatogenesis Seminiferous
tubules (left), sperm in semen (right)
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Figure 46.12 Structure of a human sperm cell
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Testosterone

• synthesized mostly by the testes in males and by
  the adrenal glands of both sexes.

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Figure 46.14 Hormonal control of the testes
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Macromolecules 3. Proteins

• The molecular tools for most cellular functions.
  
• Consist of one or more polypeptide chains folded
  into a specific shape.
• Extremely specific for the jobs they do in the
  cell.
• Are abundant,

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Proteins their functions

• They are the most diverse type of macromolecule.
  They are responsible for
• 1. Structural support
• 2.
• 3. Transport
• 4. Signaling

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Proteins their functions

• 5. Cellular response to chemical stimuli
• (receptors)
• 6. Movement (contractile proteins).
• 7. Defense
• 8.

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Figure 5.21 Spider silk a structural protein
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• Each type of protein has a unique 3-D shape.
• Despite diversity, there are only 20 amino acids
  monomers most commonly found in nature.

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• Amino acids are the building blocks of proteins.
• AA AA AA protein
• Every amino acid has
• Terminal
• Amino group
• Variable group

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Variable R group can be

• Nonpolar
• Polar
• Uncharged polar
• Charged Polar
• - acidic
• - basic

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• Polypeptides are made through condensation
  synthesis linking AA to another AA through a
  covalent peptide bond.
• Rxn always occurs at the carboxyl end of one AA
  with the amino group of the adjacent AA.

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Figure 5.16 Making a polypeptide chain
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• Proteins can range in length from a few monomers
  to over a thousand.
• Native conformation is the f(x)al shape of a
  protein under normal biological conditions.
• There are four levels to protein structure
• 1. Primary
• 2. Secondary
• 3. Tertiary
• 4. Quaternary

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Proteins Primary Level

• Primary level is just the unique sequence of
  amino acids in a protein.
• This sequence is determined
• Any change in the order can result in

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Figure 5.19 A single amino acid substitution in
a protein causes sickle-cell disease
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Proteins Secondary Level

• Is the regulated, repeated coiling folding of a
  protein.
• Coiling is stabilized by hydrogen bonds.
• There are two major types
• beta

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Proteins Secondary Level a helix

• Alpha helix is stabilized by H-bonds.
• Found in fibrous proteins (keratin collagen)
  and some globular proteins.

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Figure 5.20 The secondary structure of a protein
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Proteins Tertiary Structure

• Irregular contortions due to bonding of side
  chains (R-groups).
• Types of bonds are
• A.
• B.

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Proteins Tertiary Structure

• A. Weak interactions include
• - hydrogen bonding
• -
• - hydrophobic interactions between
• nonpolar side chains

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Proteins Tertiary Structure

• B. Covalent links disulfide bridges form
  between two cysteine monomers brought together

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Figure 5.22 Examples of interactions
contributing to the tertiary structure of a
protein
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Proteins Quaternary Structure

• Structure that results from the interaction among
  several polypeptides in a single protein.
• This is the overall shape of the protein.
• Collagen

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Figure 5.23 The quaternary structure of proteins
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Proteins

• All 4 levels of protein structure contribute to
  its shape.
• Changing any part of any level can have drastic
  effects on the proteins function.
• If a protein is altered, it may become

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Figure 5.25 Denaturation and renaturation of a
protein
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Macromolecules 4. Nucleic Acids
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Nucleic Acids

• There are two type of nucleic acids

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DNA Deoxyribonucleic Acid

• Contains coded information that programs cell
  activity.
• Is copied and passed from one generation of cells
  to another.
• Has genes that contain instructions for protein
  synthesis.
• Usually double

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DNA

• Is a polymer of nucleotides joined by
  phosphodiester linkages between the phosphate
  group of one nucleotide and the sugar of the
  next.
• This results in a backbone pattern of

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Figure 5.30 The DNA double helix and its
replication
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RNA Ribonucleic Acid

• Functions in the actual synthesis of proteins
  coded for by DNA.
• Usually single stranded.
• Flow of genetic information is

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Nucleic Acids

• Nucleic acids are polymers of nucleotides linked
  together.
• Nucleotides are the monomers they have

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Nucleic Acids

• The phosphate group is attached to the number 5
  carbon of the sugar.
• The nitrogenous base is where variation comes
  from. There are two families

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Nitrogenous Bases Pyrimidines

• Characterized by a 6-membered ring made up of
  carbon nitrogen atoms.
• Abbreviated with letters
• C (cytosine)
• T (thymine)
• U (uracil)

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Nitrogenous Bases Purines

• Characterized by a five-membered ring fused to a
  six-membered ring (are larger in size than
  pyrimidines).

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• Pyrimidines only bond with purines.
• Bonding occurs from one stand of helix to the
  other.
• It is hydrogen bonding that holds the double
  helix together.
• A always bonds with

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Figure 5.29 The components of nucleic acids