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Ch 5: The Structure and Function of Large Biological Molecules - Coggle…
Ch 5: The Structure
and Function of
Large Biological
Molecules
Carbohydrates
Monomers
Monosaccharide
Classified by
The location of the carbonyl group (as aldose
or ketose)
The number of carbons in the carbon skeleton
Glucose
C₆H₁₂O₆
most common monosaccharide
Glycosidic linkage
covalent bond between two monosaccharides
Defined as simple sugars
Disaccharide
formed when a dehydration
reaction joins two monosaccharides
Dehydration Synthesis
Making polymers by removing H₂O
Polymers
Polysaccharide
Starch
a storage polysaccharide of plants
consists of glucose monomers
Plants store surplus starch as granules within
chloroplasts and other plastids
simplest form of starch is amylose
Glycogen
a storage polysaccharide in animals
stored mainly in liver and muscle cells
Hydrolysis of glycogen in these cells releases
glucose when the demand for sugar increases
Hydrolysis
Using H₂O to break polymers into monomers.
Cellulose
a structural polysaccharide
a major
component of the tough wall of plant cells
cellulose in human food, passes through digestive tract as "insoluble fiber"
cellulose is a polymer of glucose, but
the glycosidic linkages differ
Chitin
a structural polysaccharide
is found
in the exoskeleton of bugs
Examples
Potatoes
Pasta
Bread
Sugar
Function
Immediate energy
Lipids
one class of large biological
molecules that does not include true polymers
Monomers
1
Glycerol
3
Fatty Acids
Polymer
Triglcyeride
three fatty acids are joined to glycerol
by an ester linkage
triacylglycerol
Types of Lipids
Fats
separate from water because water molecules
hydrogen-bond to each other and exclude the fats
Fatty Acids
vary in length (number of carbons) and
in the number and locations of double bonds
Saturated fatty acids
have the maximum number
of hydrogen atoms possible and no double bonds
Ex: Butter
solid at room temperature
Unsaturated fatty acids
have one or more double
bonds
Liquid at room temperature
Ex: Oils
Hydrogenation
the process of converting
unsaturated fats to saturated fats by adding
hydrogen
Hydrogenating vegetable oils also creates
unsaturated fats with trans double bonds
Trans fats may contribute more than
saturated fats to cardiovascular disease
constructed from two types of smaller
molecules: glycerol and fatty acids
Phospholipid
two fatty acids and a phosphate
group are attached to glycerol
two fatty acid tails are hydrophobic
the
phosphate group and its attachments form a
hydrophilic head
phospholipids are added to water, they
self-assemble into double-layered sheets
called bilayers
At the surface of a cell, phospholipids are also
arranged in a bilayer, with the hydrophobic tails
pointing toward the interior
The phospholipid bilayer forms a boundary
between the cell and its external environment
Steroids
Cholesterol
a type of steroid
is a component in
animal cell membranes and a precursor from which
other steroids are synthesized
A high level of cholesterol in the blood may
contribute to cardiovascular disease
Steroids
are lipids characterized by a carbon
skeleton consisting of four fused rings
Functions
Long-term energy
Protection
Insulation
Adipose tissue
cushions vital organs and
insulates the body
Examples
Oils
Butter
Wax
Steroids
Proteins
Monomers
Amino Acids
organic molecules with amino
and carboxyl groups
differ in their properties due to differing
side chains, called R groups
Polymers
Polypeptide
The bond between amino acids is a peptide bond
has a unique linear sequence of
amino acids, with a carboxyl end (C-terminus) and
an amino end (N-terminus)
Function
Build Structures
Examples
Meat & Nut products
Enzymes
Type of Proteins
Enzymatic proteins
Enzymes
Are proteins that act as catalysts to speed up chemical reactions
ends in ase
temperature & pH can denature (change shape) enxymes
extremely specific
Defensive
Storage
Transport
Hormonal
Receptor
Contractile & motor
Structural
Four Levels of Protein Structure
Primary structure
unique
sequence of amino acids
straight line
Secondary Structure
found in most proteins
folds and twists
Tertiary Structure
determined by interactions
among various side chains (R groups)
twisted, folded, and interacts with all different sides with itself
Quaternary Structure
results when a protein
consists of multiple polypeptide chains
several tertiary structures come together
What determines protein structures
Strong covalent bonds called
disulfide bridges
may reinforce the protein''s structure
Denaturation
Loss of protein structure
proteins in the
blood tend to denature at very high body
temperature
Nucleic Acids
Monomers
Nucleotides
Each nucleotide consists of a nitrogenous base, a
pentose sugar, and one or more phosphate groups
Nucleoside
The portion of a nucleotide without the phosphate
group
nitrogenous base + sugar
two families of nitrogenous bases
Pyrimidines
cytosine, thymine, and uracil
have a single six-membered ring
Purines
adenine and guanine
have a six-
membered ring fused to a five-membered ring
Polymers
DNA
phosphodiester linkage
consists of a phosphate
group that links the sugars of two nucleotides
is the bond that breaks two nucleotides
RNA
phosphodiester linkage
Functions
Genetic Information
store, transmit,
and help express hereditary information
Examples
DNA
RNA
ATP
main energy currency in all living things
Types of Nucleic Acids
DNA
Deoxyribonucleic acid
provides directions for its own replication
the sugar is deoxyribose
Gene Expression
directs synthesis of messenger RNA (mRNA)
and, through mRNA, controls protein synthesis
also called protein synthesis
Structures
double stranded/ double helix
The backbones run in opposite 5′ → 3′ directions
from each other, an arrangement referred to as
antiparallel
adenine (A) always with thymine
(T), and guanine (G) always with cytosine (C)
RNA
the
sugar is ribose
Structure
single stranded
A (Adenine) pairs with U (uracil)
guanine (G) pairs with cytosine (C)
mRNA
interacts with the cell’s
protein-synthesizing machinery to direct production
of a polypeptide