Carbohydrates and Lipids Ch 51 and Ch 52 Describe the properties of the monomers and the type of bonds that connect the monomers in biological macromolecules Explain how hydrolysis and dehydration synthesis are used to cleave and form covalent bonds between monomers ID: 780063
Download The PPT/PDF document "1 The Structure and Function of Macromol..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
1
The Structure and Function of Macromolecules:
Carbohydrates and Lipids
(Ch. 5-1 and Ch. 5-2)
Slide2Describe the properties of the monomers and the type of bonds that connect the monomers in biological macromolecules.
Explain how hydrolysis and dehydration synthesis are used to cleave and form covalent bonds between monomers.
Explain how complex carbohydrates are comprised of sugar monomers whose structures determine the properties and functions of the molecules.
Learning Objectives
Slide3Explain why lipids are nonpolar.
Explain how the differences in saturation determine the structure and function of lipids.
Describe how phospholipids contain polar regions that interact with other polar molecules, such as water, and with nonpolar regions that are often hydrophobic.
Learning Objectives
Slide4The FOUR Classes of Large Biomolecules
All living things are made up of four classes of large biological molecules:
Carbohydrates
Lipids
Protein
N
ucleic Acids
Macromolecules
are large molecules composed of thousands of
covalently bonded atomsMolecular structure determines function
4
Slide5The FOUR Classes of Large Biomolecules
Macromolecules are polymers, built from
monomers covalently bonded together
A polymer is a long molecule consisting of many similar building blocks
These small building-block molecules are called
monomers
5
Slide6The FOUR Classes of Large Biomolecules
Three
of the four classes of life’s organic molecules are polymersProteins
Nucleic Acids
Carbohydrates
6
Slide7Dehydration Synthesis and Hydrolysis
D
ehydration synthesis - occurs when two monomers bond together through the loss of a water
molecule
(AKA: condensation reaction)In hydrolysis
- polymers are disassembled to monomers by a reaction that is essentially the
reverse of the dehydration reaction
7
Slide8Dehydration Synthesis
8
e
-
e
-
__________
Slide9Hydrolysis
9
Slide10Carbohydrates
Carbohydrates -
Serve as readily available energy for living things.
Usually end in –
ose.
Carbohydrates
include
sugars and the polymers of
sugarsMonosaccharides – are the simplest carbohydrates, or monomers of a single sugarPolysaccharides – are carbohydrate macromolecules, or polymers composed of many sugar building blocks 10
Slide11Sugars: Monosaccharides
Monosaccharides
have molecular formulas that are usually multiples of
CH
2
O
Glucose (C
6
H
12O6) is the most common monosaccharideMonosaccharides are classified by
The location of the carbonyl
group
The number of carbons in the carbon skeleton
11
Slide1212
Slide1313
Slide14Sugars: Disaccharides
A
disaccharide is formed when a dehydration reaction joins two monosaccharides
This covalent bond is called a
glycosidic linkage
14
Slide15Disaccharides
15
Slide16Counting Carbons in Carbohydrates
16
Slide17Synthesizing Maltose & Sucrose
17
Slide18Polysaccharides
Polysaccharides
, the polymers of sugars, have storage and structural roles
The structure and function of a polysaccharide are determined by its sugar monomers and the positions of glycosidic linkages
18
Slide19Types of Polysaccharides: Storage
Starch
, a storage polysaccharide of plants, consists entirely of glucose monomers
Plants store surplus starch as granules within chloroplasts and other plastids
The simplest form of starch is amylose
19
Slide20Structure of Starches
20
Slide21Types of Polysaccharides: Storage
Glycogen
is a storage polysaccharide in animals
Humans and other vertebrates store glycogen mainly in liver and muscle cells
21
Slide22Structure of Glycogen
22
Slide23Types of Polysaccharides: Structural
The polysaccharide
cellulose is a major component of the tough wall of plant
cells
To digest cellulose, organisms must produce the enzyme
cellulase
(humans don’t produce this enzyme)
Like starch, cellulose is a polymer of glucose, but the glycosidic linkages
differ
Remember…change the structure, change the function…23
Slide24Types of Polysaccharides: Structural
The
difference between starch & cellulose
is based on two ring forms for glucose: alpha (
) and beta (
)
24
Slide25(a)
and
glucose
ring structures
(b) Starch: 1–4 linkage of
glucose monomers
(c) Cellulose: 1–4 linkage of
glucose monomers
Glucose
Glucose
4
1
4
1
4
1
4
1
Structure of Starch vs Cellulose
Slide26Structure of Cellulose
26
Slide2727
Slide2828
Slide29Polysaccharide
Random Acts of Biology
Cellulose
in human food passes through the digestive tract as insoluble fiber
Some microbes use enzymes to digest
cellulose
Many herbivores, from cows to termites, have symbiotic relationships with these
microbes
Chitin, another structural polysaccharide, is found in the exoskeleton of arthropods (crunch!)Chitin also provides structural support for the cell walls of many fungi29
Slide30Polysaccharides (Storage or Structure)
30
Slide31Who knew?
31
Slide32Explain why lipids are nonpolar.
Explain how the differences in saturation determine the structure and function of lipids.
Describe how phospholipids contain polar regions that interact with other polar molecules, such as water, and with nonpolar regions that are often hydrophobic.
Learning Objectives
Slide33Lipids
Lipids
– vary in form and function, provide stored energy & insulation and cell membrane structure for living things.
The most biologically important lipids are fats, phospholipids, and steroids
The
unifying feature of lipids is having little or no affinity for
water (water fearing)
Lipids are hydrophobic
because
they consist mostly of hydrocarbons, which form nonpolar covalent bonds33
Slide34Structure of Lipids
Lipids
are the one class of large biological molecules that do not form
polymers
Fats (or triglycerides)
are
constructed from two types of smaller molecules: glycerol and fatty acids
Glycerol
is a three-carbon alcohol with a hydroxyl group attached to each carbon
34
Slide3535
A
fatty acid
consists of a carboxyl group attached to a long carbon skeleton
Slide36Dehydration Reaction THREE Times!!!
One fat molecule is produced by 3 dehydration reactions to join the fatty acids to the glycerol with bonds called
ester linkages
.
Bond between fatty acid & -OH
36
Slide37Saturated Fats
Fats made from
saturated fatty acids are called saturated fats, and are solid at room temperature
Most animal fats are
saturated (lard)
Saturated fatty acids
have the maximum number of hydrogen atoms possible and
no double bonds
37
Slide38Saturated Fats
38
Slide39Saturated Fats
39
A diet rich in saturated fats may contribute to cardiovascular disease through plaque
deposits
Hydrogenation
is the process of converting unsaturated fats to saturated fats by adding
hydrogen
A pair
of hydrogen atoms must be “added” across the double bond to form 2 covalent bonds between 2 different carbons and the 2 different hydrogen atoms added. Ex. Peanut butter & margarine – hydrogenated to prevent lipids from separating out in liquid
Slide40Unsaturated Fats
40
Fats made from
unsaturated
fatty acids are called unsaturated fats or oils, and are liquid at room
temperature
Plant
fats and fish fats are usually
unsaturated
Unsaturated fatty acids have one or more double bonds
Slide41Unsaturated Fats
41
Unsaturated means a PAIR of H’s is now “missing” thus a double bond forms between neighboring C’s in the carbon chain of the fatty acid.
This
causes a “bend” or “kink” in the chain which alters the shape or conformation of the fat.
Slide42Unsaturated Fats
42
Polyunsaturated fats have more than one double bond
Slide43What’s a Trans fat?
43
Hydrogenating
vegetable oils also creates
unsaturated fats
with
trans
double bonds
These
trans fats may contribute more than saturated fats to cardiovascular disease
Slide44Choline
Phosphate
Glycerol
Fatty acids
Hydrophilic
head
Hydrophobic
tails
(c) Phospholipid symbol
(b) Space-filling model
(a) Structural formula
Hydrophilic head
Hydrophobic tails
Phospholipids
Phospholipids
– specialized lipid that makes up major component of all cell membranes
Slide45Phospholipid Bilayer
When
phospholipids are added to water, they self-assemble into a bilayer, with the hydrophobic tails pointing toward the inward and hydrophilic heads pointing towards intracellular and extracellular fluid (water)
The structure of phospholipids results in a bilayer arrangement found in cell membranes
45
Slide46Steroids
Steroids
are lipids characterized by a carbon skeleton consisting of four fused rings
Cholesterol
, an important steroid,
helps stabilize animal
cell
membranes
Although cholesterol is essential in animals, high levels in the blood may contribute to cardiovascular disease
46
Slide47Learning Objectives Summaries