Transcript Macromolecules ppt

MACROMOLECULES OF LIFE
Found in all living things
Building blocks of all cells
Made up of the atoms: Carbon, oxygen,
hydrogen, Nitrogen, Phosphorus, and
Sulfur
There are 4
1.
2.
3.
4.
Carbohydrates  C, H, & O
Lipids  C, H, & O
Proteins  C, H, O, N, & S
Nucleic Acids  C, H, O, N, & P
Carbohydrates
Basic units: sugars
Provide energy and
structural support
Fiber is a carbohydrate that
prevents constipation
Foods: breads, cereals,
vegetables, fruits, & seeds
Extra glucose is converted
into glycogen in the liver
Glucose
Test for Simple Carbohydrates
Benedict’s solution • Benedict's solution is a
chemical indicator for simple sugars such as
glucose: C6H12O6.
• Aqua blue: negative test; yellow/green/brick red,
etc.: positive test
Test for Complex
Carbohydrates
Test for Complex Carbohydrates Iodine Solution
• Iodine solution Æ color change = blue to black
Lipids/Fats
Basic units: fatty acids
Functions: provides energy &
structure, cushions the body,
and prevents heat loss
Found in butter, margarine,
candy
made of fatty acid molecules
that consist of two distinct
regions:
 a long hydrophobic hydrocarbon chain
 a hydrophilic head
Test for lipids
Test for Fats (lipids) Sudan IV • If lipids are
present the Sudan IV will stain them
reddish‐orange (positive test). Also used is
the paper bag method. If the bag shows a
grease spot then there are fats present.
Saturated Fats
contain single carbon-to-carbon bonds
has lots of hydrogen
solid at room temperature (beef, pork,
chicken, dairy)
found in animal products
Reduce Intake!  can clog blood vessels
Unsaturated Fats
contain double or triple carbon-to-carbon
bonds & fewer hydrogen atoms
Liquid at room temperature (oils, nuts, &
seeds)
found in plant products
Better Intake!
Molecular structures of Fats
Saturated Fat
Unsaturated Fat
DNA Structure discovery
James Watson and
Francis Crick with
DNA Model in
1953.
Nucleic Acids
Atoms: C, H, O, N, P
Basic units: nucleotides composed of 
Sugar
Phosphate group
Base: cytosine, guanine, adenime, thymine, uracil
There are two types:


DNA (deoxyribonucleic acid)
RNA (ribonucleic acid)
Function: DNA directs & controls all activities of all cells
in an organism – RNA helps
DNA –
DeoxyriboNucleic Acid
DNA is the hereditary
material passed on
from parents to
offspring
Structure: doublestranded



Phosphate group
Sugar  deoxyribose
Bases 
Cytosine – Guanine
Adenine – Thymine
RNA
RNA helps the DNA
RiboNucleic Acid
Structure: singlestranded
Basic units: nucleotides



Phosphate group
Sugar  ribose
Bases 
Cytosine – Guanine
Adenine – Uracil
Nitrogenous Bases
Proteins
Atoms: C, H, O, N, S
Basic units: amino acids (20)
Provide energy & structure, repairs body
tissues
Some are called hormones, enzymes,
neurotransmitters, etc.
Foods high in protein: meat, eggs, poultry,
milk & milk products, nuts, dried beans,
peas, & lentils
Proteins
Primary Structure
The very basic strand of amino
acids
Secondary Structure
The hydrogen-bond
interaction among strands of
amino acids giving alpha
helices and beta-sheets
shapes .
Proteins
Tertiary Structure
Quaternary Structure
Interaction between alpha
helices and beta-sheets.
These protein domains
for small globular
proteins.
Small globular proteins
form protein aggregates.
A famous example is
hemoglobin.
Protein Structures
Protein Structures (Cont’d)
Enzymes
Are proteins
Speed up chemical reactions
without being consumed or
using energy
Enzymes




Amylase - breaks down sugar
Proteases - break down proteins
Lipases - break down lipids
Catalase - breaks down hydrogen
peroxide
Enzyme Action Models
Models
Enzyme Action Models
lock and key model  substrate & the
enzyme fit together perfectly
induced-fit model  Enzyme changes
shape slightly to accommodate the
substrate
Factors that affect enzyme action:
1. Temperature – 37oC best for human
enzymes
2. pH – different for each enzyme
a.
b.
c.
7 for amylase in the mouth
2 for pepsin in the stomach
8 for trypsin in the intestines
3. Concentration of enzyme and substrate
4. Coenzymes – helpers such as minerals and
vitamins
Macromolecules parts of the cell
Membrane