Topic Two: Biochemistry CarbohydratesLipidsProteins Nucleic Acids.
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Transcript of Topic Two: Biochemistry CarbohydratesLipidsProteins Nucleic Acids.
Topic Two: BiochemistryTopic Two: BiochemistryCarbohydratesCarbohydrates
LipidsLipidsProteinsProteins
Nucleic AcidsNucleic Acids
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Four Types of Organic MoleculesFour Types of Organic Molecules• There are 4 major types of organic molecules important in biology.
Carbohydrates
monosaccharides, disaccharides,
polysaccharidesLipids
Triglycerides, Phospholipids,
Waxes, Steroids
Proteins
Primary, Secondary, Tertiary, Quaternary
Nucleic Acids
DNA, RNA
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MetabolismMetabolism• Metabolism: All the chemical
reactions that occur in the body.– Can be catabolic or anabolic– Over 200,000 reactions occur in your Over 200,000 reactions occur in your
body cellsbody cells• Monomers are basic subunits used
to build larger molecules. – Eg. Amino acids
• Polymers are molecules composed of many monomers bonded together– Eg. Many amino acids bond together
to form a protein.
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Catabolic vs. Anabolic ReactionsCatabolic vs. Anabolic ReactionsCatabolic Reactions:• Larger molecules
(polymers) break down into smaller units (monomers)
• Ex. Digestion (breaking down food)
Anabolic Reactants:• Small units (monomers)
combine to make larger molecules (polymers)
• Ex. Plants and photosynthesis
Catabolic Reactions
Anabolic Reactions
Polymers Polymers
Monomers
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Monomer:
Amino acid
Polymer:
Protein
Ex: Proteins in the human body
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HydrolysisHydrolysis
• Larger molecule is broken down using water• Water is taken up at the broken bond site
+
H2O
“water” “to cut”
CATABOLIC !!
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Dehydration SynthesisDehydration Synthesis
• Larger molecules are formed by removing water
+
H2O
“To take water out” “To make”
ANABOLIC !!
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Catabolic vs. Anabolic ReactionsCatabolic vs. Anabolic Reactions
How to Remember these terms:CHAD: Catabolic – Hydrolysis,
Anabolic – Dehydration Synthesis
• Carbohydrates are the body’s most important source of energy!
• The human body cannot make carbohydrates itself
• We must consume plants for carbohydrates.
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Topic 2-2: CarbohydratesTopic 2-2: Carbohydrates
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Characteristics of CarbohydratesCharacteristics of Carbohydrates• A carbohydrate can be a single sugar or
polymer of many sugars• Carbohydrates are composed of carbon
(C), hydrogen (H), and oxygen (O)– Ratio of carbon, hydrogen, oxygen =
1:2:1– Ex. Glucose C6H12O6
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Two Purposes of CarbohydratesTwo Purposes of CarbohydratesStructural
Major structural component of cell organelles, membranes, cell wall
Ex. cellulose
Energy
Produced by photosynthesis, carbohydrates are the major energy source for cells. Energy is released
through cell respiration
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Types of CarbohydratesTypes of CarbohydratesMonosaccharides
“1 sugar unit”
Ex: glucose/fructose
Disaccharides
“2 sugar units”
Ex: sucrose
Polysaccharides
“many sugar units”
Ex: starch/ glycogen
Classified by the
number of sugar
units they contain
How are disaccharides and polysaccharides formed?
Dehydration Synthesis!!
CarbohydratesCarbohydrates
+
H2O
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MonosaccharidesMonosaccharides• Monosaccharides
are made of single sugar units
• Examples include:– glucose– fructose
– These are all isomers • Same chemical
formula C6H12O6
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Types of MonosaccharidesTypes of Monosaccharides
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Use the chart to help fill in your workbooksUse the chart to help fill in your workbooks Monosaccharide Origin Purpose
Glucose
Fructose
From food, found in human blood plasma + all cells
Main source of fuel for cells
Found in fruits and honey. Twice as sweet as glucose
Sweetest naturally occurring carbohydrate. Used for sweeteners.
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DisaccharidesDisaccharides• Formed by the joining of two monosaccharides
– Process called dehydration synthesis (water molecule is extracted from the two monosaccharide sugar molecules that come together)
Disaccharides: aka double sugars!!!
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Disaccharides - SucroseDisaccharides - Sucrose
Ex: glucose + fructose make sucrose and water The reverse process is called HYDROLYSIS (uses water)
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Three Common DisaccharidesThree Common DisaccharidesDisaccharide(ISOMERS)
Monomers General comments
Sucrose Glucose + Fructose From sugar cane plant, used as table sugar
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PolysaccharidesPolysaccharides: : AKA AKA Complex CarbohydratesComplex Carbohydrates
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PolysaccharidesPolysaccharides• Formed by the union of many monosaccharides by
dehydration synthesis
Major Role a) Energy Major Role a) Energy StorageStorage
energy storage molecles in organisms are starch (plants) glycogen (animals)
liver
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PolysaccharidesPolysaccharides
Major Role b) Structural Major Role b) Structural SupportSupport
such as cellulose (plants) and chitin (exoskeletons)
Important PolysaccharidesImportant Polysaccharides
What are the two important polysaccharides used for energy storage in
organisms?
STARCH (PLANTS) and GLYCOGEN (ANIMALS)
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StarchStarch• Monomers used: glucose• Function: energy storage in
plants• Other: Glucose molecules
that are not required for growth or energy in the cell are linked together to form starch
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GlycogenGlycogen
• Monomers used: glucose• Function: Storage of glucose in
animals (liver and muscle cells)– High Blood Glucose -Glycogen formed in
the liver– Low Blood Glucose -Glycogen is broken
down • Other: When energy is needed by
the cell, stored glycogen is broken down into glucose molecules to be used for energy
Darker meats mean most of the stored
glycogen has broken down into lactic acid
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CelluloseCellulose• Monomers used: glucose • Function: Main structural
material in plant cell walls• Other: The bonds between the
glucose molecules are difficult to break, so cellulose is not easily digested. – Cotton, wood and wood products like
paper are almost entirely made of cellulose!
– Digestion in cows, horses, goats and termites is done by microorganisms that live in their digestive tracts
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Why can’t we digest Why can’t we digest cellulose??cellulose??
• Humans don’t have cellulase – an enzyme to break down cellulose)
• But… we still need cellulose (aka fiber) to hold water in the large intestine, and help eliminate wastes
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Topic 2-3: LipidsTopic 2-3: Lipids• Lipids are insoluble (do not dissolve) in water • Contains carbon, hydrogen, and oxygen
• Ratio of H to O is greater than 2 to 1• Examples include
– triglycerides– phospholipids– steroids
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Purposes of LipidsPurposes of Lipids• Long Term Energy Storage
– Lipids are long term energy storage molecules
• contain more than twice the calories compared to carbohydrates or proteins
• Structural Material–cell membranes–cushion for organs–carriers for vitamins–raw materials for synthesis of hormones–insulators
Types of Lipids: TriglyceridesTypes of Lipids: Triglycerides• Triglycerides
– Commonly known as fat– Formed from one glycerol and 3 fatty acids by
dehydration synthesis
glyc
erol
Fatty Acid #1
Fatty Acid #2
Fatty Acid #3
O
O
O
Triglyceride (fat)
Total = 3 waters produced
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2 Types of Fatty Acids:2 Types of Fatty Acids:• SATURATED FAT
– Source: usually from animals
– Single/double bond: only single bonds between carbon atoms
– Reactivity: Very Stable -- hard to break down
– Solid/liquid: solid or semi-solid at room temperature
– Example: butter
UNSATURATED FAT• Source: usually from plants• Single/double bond:
unsaturated fatty acids have some double bonds between carbon atoms
• Reactivity: more reactive than fats and easy to break down
• Solid/liquid: liquid at room temperature
• Example: Canola oil
Types of Fatty AcidsTypes of Fatty Acids
http://www.youtube.com/watch?v=RiYOuI7iyp8&safety_mode=true&safe=active
Bill Nye- clots 4:30 – 6:18http://www.youtube.com/watch?v=YlCX2NCEgcM&safety_mode=true&safe=active
Bill Nye- Fat is bad. Fruit, veg good 1:53 – 3:23
https://www.youtube.com/watch?v=KG_ybdk1VaE ASAP Science – butter vs. margarine 3:09
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Types of Lipids: PhospholipidsTypes of Lipids: Phospholipids• Phospholipids are a major component of cell membranes• Formed from one glycerol, two fatty acids and one
phosphate
glyc
erol
Fatty Acid #1
Fatty Acid #2
Phosphate
O
O
O
Hydrophilic
Hydrophobic
Cell MembraneCell Membrane
– Phosphate replaces one of the fatty acids • Phosphate is hydrophilic (polar)• Fatty acid tails are hydrophobic (nonpolar)
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Types of Lipids: Steroids
• Structure = four fused carbon rings• Function = building material for hormones, bile etc• Common examples are cholesterol and testosterone
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Effects of Steroids
• Read: “The Cholesterol Controversy” • Answer questions 1 – 5 in your workbook
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Homework Assignment
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Cholesterol ControversyCholesterol Controversy1. What is Cholesterol?• Cholesterol is a waxy steriod of fat. (abundant
in animal fats, brain and nerve tissue, meat and eggs)
• functions in the body as a membrane constituent and as a precursor of steroid hormones and bile acids.
2. Why has cholesterol been so important to health conscious consumers?
• levels in the blood are associated with arteriosclerosis, gall stones and heart disease!
• People with a certain genetic makeup are predisposed to arteriosclerosis…Can lead to heart disease!!!!!
Arthrosclerosis
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LDLs vs. HDLsLDLs vs. HDLs3. What do HDL and LDL stand for?• HDL = High Density Lipoprotein, • LDL = Low Density Lipoprotein 4. What is the function of HDL’s and LDL’S?Low-density lipoprotein is the major cholesterol carrier in the blood • LDL’s are “bad cholesterol”• High levels of LDLs have been associated with the clogging of arteries known as a
plaque• Plaque restricts blood flow to the heart + brain & can lead to heart attack or stroke
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• HDLs (which are good!) carry LDLs back to the liver, which begins breaking it down
• High density lipoproteins lower blood cholesterol• eating a balanced diet, exercising, and stopping tobacco
use, medications can increase HDLs!!
State the function of HDLs & LDLsState the function of HDLs & LDLs
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Cholesterol & DietCholesterol & Diet• People get cholesterol in two
ways– The liver produces cholesterol– Foods contain cholesterol – especially
egg yolks, meat, poultry, fish, seafood and whole-milk dairy products
• Typically the body makes all the cholesterol it needs (no need to consume)
• What increases blood cholesterol?– Consuming saturated fatty acids– Eating trans fats– Both may lead to heart disease
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Cholesterol & DietCholesterol & Diet5. How can you decrease your
cholesterol intake?• keeping dietary intake of saturated
fats low can significantly lower your dietary cholesterol
• Eat no more than six ounces of lean meat, fish and poultry per day and use fat-free and low-fat dairy products
• vegetable sources such as beans are good substitutes for animal sources of protein
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Cholesterol & ExerciseCholesterol & Exercise5. How can you decrease your
cholesterol?• Exercising lowers LDLs• Being overweight tends to increase
the amount of low-density lipoprotein (LDL) in your blood.
• Fibre and cellulose lower LDLs• Higher intensity exercise lowers the
LDLs more than moderate exercise does. It also raises HDLs more.
NOTE:Genetics, weight, age, gender, and diet
all contribute to an individual's cholesterol profile.
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Triglicerides videoTriglicerides video
http://www.youtube.com/watch?v=VGHD9e3yRIU