Macromolecules

advertisement
Biology I
1
Organic Compounds
Compounds that
contain CARBON
are called organic
compounds.
 Organic chemistry
is the study of
carbon compounds
Although a cell is
mostly water, the
rest of the cell
consists mostly of
carbon-based
molecules
2
Giant Molecules = Polymers
Large molecules are
called polymers
Polymers are built
from smaller
molecules (building
blocks) called
monomers
 Biologists call them macromolecules
3
 Large organic molecules.
 Also called POLYMERS.
 Made up of smaller “building blocks”
called MONOMERS.
Examples:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids (DNA and RNA)
4
Most Macromolecules are Polymers
Polymers are made by stringing
together many smaller molecules called
monomers
Nucleic Acid
Monomer
5
Macromolecules in Organisms
• There are four categories of large
molecules in cells:
Carbohydrates
Lipids
Proteins
Nucleic Acids
6
 Carbohydrates are compounds
composed of C,H,& O atoms in the
ratio of 1:2:1
 The monomers are sugar molecules
They include:
Small sugar molecules in soft drinks
Long starch molecules in pasta and
potatoes
Consist of 3 major types of
sugars:
Monosaccharides
 Disaccharides
 Polysaccharides
7
Monosaccharides:
Called simple sugars
Include glucose,
fructose, & galactose
Have the same
chemical, but
different structural
formulas
C6H12O6
8
Monosaccharides
Glucose is found in
sports drinks
Fructose is
found in fruits
Honey contains
both glucose &
fructose
Galactose is
called “milk sugar”
9
Isomers
• Glucose &
fructose are
isomers because
they’re
structures are
different, but
their chemical
formulas are the
same
10
Cellular Fuel
Monosaccharides are
the main fuel that cells
use for cellular work
ATP
11
Disaccharides
A disaccharide is a
double sugar
They’re made by
joining two
monosaccharides
Common disaccharides
include:
►Sucrose (table sugar)
►Lactose (Milk Sugar)
►Maltose (Grain sugar)
12
Disaccharides
Sucrose is
composed of
glucose + fructose
 Maltose is
composed of 2
glucose molecules
 Lactose is made
of galactose +
glucose
GLUCOSE
13
Polysaccharides
Complex
carbohydrates
Composed of many
sugar monomers
linked together
Polymers of
monosaccharide
chains
14
Examples of Polysaccharides
Glucose Monomer
Starch
Glycogen
Cellulose
15
Starch
Starch is an
example of a
polysaccharide in
plants
Plant cells store starch
for energy
Potatoes and grains are
major sources of starch in
the human diet
16
Glycogen
Glycogen is an
example of a
polysaccharide in
animals
Animals store
excess sugar in
the form of
glycogen
Glycogen is similar in
structure to starch
17
Cellulose
►Cellulose is the most abundant
organic compound on Earth
►It
forms cable-like fibrils in the tough walls
that enclose plants
►It
is a major component of wood
►It
is also known as dietary fiber
18
Cellulose
SUGARS
19
Large molecules composed of mostly carbon &
hydrogen atoms
Lipids are hydrophobic –”water fearing”
They’re not soluble in water
Includes
fats,
waxes, steroids,
& oils
FAT MOLECULE
20
Function of Lipids
• Fats store energy, help to insulate
the body, cushion and protect
organs.
21
Types of Fatty Acids
Unsaturated fatty acids~ have less than
the maximum number of hydrogens bonded
to the carbons (a double bond between
carbons). Usually liquids at room temp.
Saturated fatty acids~ have the maximum
number of hydrogens bonded to the carbons (all
single bonds between carbons). Usually solids at
room temp.
22
Fats in Organisms
• Most animal fats have a high proportion of
saturated fatty acids & exist as solids at room
temperature (butter, margarine, shortening)
23
Fats in Organisms
• Most plant oils tend to be low in
saturated fatty acids & exist as
liquids at room temperature (oils)
24
Types of Fatty Acids
Single
Bonds in
Carbon
chain
Double bond in carbon chain
25
Triglyceride
Monomer of lipids
Composed of
Glycerol & 3
fatty acid chains
Glycerol forms
the “backbone”
of the fat
26
Triglyceride
Glycerol
Fatty Acid Chains
27
Steroids
The carbon skeleton
of steroids is bent to
form 4 fused rings
Cholesterol is the
“base steroid” from
which your body Testosterone
produces other
steroids
Cholesterol
Estrogen
Estrogen & testosterone are also steroids
28
Synthetic Anabolic Steroids
They are variants
of testosterone
Some athletes use
them to build up their
muscles quickly
They can pose
serious health risks
29
Are macromolecules that contain the
element N as well as C, H, & O.
Proteins are polymers made of
monomers called amino acids
 All proteins are made of 20 different
amino acids linked in different orders
 Proteins are used to build cells, act as
hormones & enzymes, and do much of the work
in a cell
30
Four Types of Proteins
Storage
Structural
Contractile
Transport
31
20 Amino Acid Monomers
32
Structure of Amino Acids
Amino acids have
a central carbon
with 4 things
bonded to it:
Carboxyl
group
Amino
group
R group
Amino group -NH3
Carboxyl group -COOH
Hydrogen
Side group
-H
-R
Side
groups
33
Linking Amino Acids
Carboxyl
Amino
Cells link amino
acids together to
make proteins
Peptide bonds
form to hold the
amino acids
together
Side
Group
Peptide Bond
34
Proteins as Enzymes
Many proteins act as biological
catalysts or enzymes & end in ase
Thousands of different enzymes exist
in the body
Enzymes control the rate of chemical
reactions by weakening bonds, thus
lowering the amount of activation energy
needed for the reaction
35
Enzymes
Enzymes are globular
proteins.
Their folded conformation
creates an area known as the
active site.
The nature and arrangement
of amino acids in the active site
make it specific for only one
type of substrate.
36
Enzyme + Substrate = Product
37
How the Enzyme Works
Enzymes are reusable!!!
38
Primary Protein Structure
The primary
structure is
the specific
sequence of
amino acids in
a protein
Amino Acid
39
Protein Structures
Secondary protein structures
occur when protein chains coil or
fold
When protein chains called
polypeptides join together, the tertiary
structure forms
In the watery environment of a cell,
proteins become globular in their
quaternary structure
40
Protein Structures
Amino acid
(a) Primary structure
Alpha helix
(b) Secondary
structure
(c) Tertiary
structure
(d) Quaternary structure
41
Changing Amino Acid Sequence
Substitution of one amino acid for
another in hemoglobin causes sickle-cell
disease
1
2
(b) Sickled red blood cell
6
7
4
5
Normal hemoglobin
(a) Normal red blood cell
1
3
2
3
6
7
4
5
Sickle-cell hemoglobin
42
Macromolecules that contain
H, O, N, C,& P.
Store hereditary information
Contain information for making all
the body’s proteins
Two types exist - DNA & RNA
43
44
Nucleic Acids
Nitrogenous base
(A,G,C, or T)
Nucleic
acids are
polymers of Phosphate
group
nucleotides
Thymine (T)
Sugar
(deoxyribose)
Phosphate
Base
Sugar
Nucleotide
45
Bases
• Each DNA
nucleotide has
one of the
following bases:
Thymine (T)
Cytosine (C)
–Adenine (A)
–Guanine (G)
–Thymine (T)
–Cytosine (C)
Adenine (A)
Guanine (G)
46
Nucleotide Monomers
Backbone
Form long
chains called
DNA
Nucleotide
Nucleotides are
joined by sugars &
phosphates on the
side
Bases
DNA strand
47
DNA
Two strands of
DNA join together
to form a double
helix
Base
Has the sugar
pair
deoxyribose
Bases are:
A, T, C, & G
Double helix
48
RNA – Ribonucleic Acid
Has the sugar
ribose
Single stranded
It has the base
uracil (U)
instead of
thymine (T)
A,U,C & G
Nitrogenous base
(A,G,C, or U)
Uracil
Phosphate
group
Sugar (ribose)
49
Nucleic Acids
50
51
Macromolecules
52
Macromolecules
53
Download