ORGANIC CHEMISTRY Carbohydrates, Proteins and Fats.
-
Upload
sheryl-jefferson -
Category
Documents
-
view
234 -
download
3
description
Transcript of ORGANIC CHEMISTRY Carbohydrates, Proteins and Fats.
ORGANIC CHEMISTRYCarbohydrates, Proteins and Fats
All forms of energy are not equally capable of doing physiological work.
• We are not capable of using heat to do any form of physiological work…it is wasted energy.
Physiological Work
Examples of Physiological Work
•Synthesis of macromolecules such as proteins, carbohydrates and lipids
•Generation of electrical or chemical gradients
•Muscle Contraction
MAX KLIBER: THE FIRE OF LIFE
•Life is a combustion process•You are using oxygen to burn fuel (food) to create energy (and
waste heat)
OxygenOxygen
HeatHeat
MetabolismMetabolism
YOU CONSUME O2 & FOOD TO PRODUCE ENERGY
Hydrocarbon Fuel + O2 CO2 + H2O
Heat
Combustion in a Pop Bottle Demonstration
EACH “FUEL” DEMONSTRATES A RELATIONSHIP BETWEEN THE AMOUNTS OF: •O2 consumed •ATP produced •CO2 produced
Mechanisms of Energy (ATP) Production
Oxidative Phosphorylation• 5-10 seconds
Anaerobic Respiration• 1-2 minutes
Aerobic Respiration• Conditioning dependent
All 3 major categories of food can be degraded through these processes
CARBOHYDRATE CARBOHYDRATE METABOLISMMETABOLISM
Carbohydrates are present in food in various forms: Simple sugars:
Monosaccharides
Complex chemical units: Dissacharides Polysaccharides
Digestion of Carbohydrates
Carbohydrates Ingested Mechanical Digestion via chewing Broken down into monosaccharides Absorbtion in stomach, duodenum and
proximal jejunum
BLOOD GLUCOSE REGULATIONThe Liver and Pancreas
The Role of the Liver1. Simple sugars enter freely into liver2. Galactose and Fructose are enzymatically converted to
glucose3. Glucose is stored in the liver and only the liver can release
glucose into the blood stream.4. When glucose is readily available it is incorporated into
glycogen for storage via glycogenesis.5. When blood glucose drops glucose can be released from
glycogen via glycogenolysis
Pancreatic Secretions
1. Insulin: lower blood glucose level2. Glucagon: raise blood glucose level3. Epinephrine: raise blood glucose level
CARBOHYDRATES:the major source of energy (ATP)for the body
Monosaccharidea simple sugar with the formula CxH2xOx
Galactose Glucose Fructose
Disaccharide:
2 simple sugars bonded together
The formula for a disaccharide is one oxygen and two hydrogens short of the
1:2:1 ratio because a water is removed in the bonding process.
Sucrose: table sugar Lactose: milk sugar Maltose: grain sugar
Polysaccharidemore than 2 simple sugars bonded
together
Glycogen Starch
Cellulose (can not be digested)
Glucose and the Liver Simple sugars enter the liver and
enzymes convert them to glucose The liver can release its glucose stores
as necessary or absorb blood glucose. Excess blood glucose triggers release of
glycogen which absorbs excess glucose
Carbohydrate DigestionPolysaccharides
Salivary Amylase(mouth)
Pancreatic Amylase
(small intestine)
DisaccharidesLactase
Maltase & Sucrase
(small intestine)
Lactose Maltose Sucrose
Galactose Glucose Fructose
Carbohydrate Facts monosaccharides enter the capillary blood. causes blood sugar to rise triggering the pancreas to
release insulin which is needed to move sugar from blood into cells.
When this process goes fast - as with simple sugars - you're more likely to feel hungry again soon and blood sugar will rise more rapidly or spike.
When it occurs more slowly, as with a whole-grain food, you'll be satisfied longer. These types of complex carbohydrates give you energy over a longer period of time and will cause blood sugar to rise more slowly and evenly.
If you have consumed more carbohydrates than your body needs, the glucose will be turned into glycogen and stored in your muscles and liver for use in the future. When the liver and muscle tissues exceed their capacity for storing glycogen, the excess is converted into fat.
PROTEINlarge complex molecules made up of one or more chains of amino acids held together by peptide bonds
METABOLISM OF PROTEINAmino Acids
Protein Structure: Made up of a combination of about 20
naturally occurring amino acids Joined by Peptide Bonds Carboxyllic acid and an amino group
Role of the Liver: Amino Acids stored in liver, blood stream
and body tissues Amino Acids can be transferred from one
of these locations to another Amino acids are stored by deamination
so that they can be used as an energy source (ATP)
Amino Acids as a Fuel Source Amino acids are only used as a fuel
source during starvation When there is an abundance of amino
acids they are converted into glucose (gluconeogenesis) and fatty acids and glycerol (lipogenesis)
Waste Products of Protein Metabolism Deamination forms ammonia which is
toxic The liver detoxifies ammonia by
converting it into the less toxic, water soluble substance urea.
Hormones and Protein Metabolism Human growth hormone and insulin
increase the uptake of amino acids and protein synthesis in muscle tissue.
Thyroid hormones also regulate protein metabolism
Androgens from the testes and the adrenal gland stimulate protein synthesis.
PEPTIDE BONDSwhen 2 amino acids bond water is removed (dehydration synthesis) leaving a carbon and a nitrogen directly bonded to one another
Types of Protein Dietary Proteins: ingested protein Enzyme Proteins: secretions from GI
tract and other various glands Body Proteins: sloughed off and
disintegrating mucosal layer cells
Amino acids can be converted into glucose by a series of processes.
This happens primarily during starvation.
Amino Acids
Protein
Large Polypeptides
Small Polypeptides
Pepsin (stomach)
Trypsin Chymotrypsin & Carboxypeptidasesecreted by pancreas
(small intestine)
Aminopeptidases Carboxypeptidase
& Dipeptidases(small intestine)
Protein Facts The amino acids are absorbed by the blood capillaries of the
small intestines, carried through the liver, and then go into the blood of the general circulation
Various body cells take what they need to repair and reform the protein structures they need.
Skeletal muscles act as an emergency source of protein if insufficient amounts are eaten. The body can break down its own muscle tissue, and transport the amino acids gathered from that muscle destruction to the more vital organs, if necessary.
People on very low fat diets are by default, on low protein diets. This is because most of the rich sources of protein in foods are also in sources of dietary fat. These dieters lose their muscle mass because their bodies cannibalize their own muscles as a source of the proteins that they need, but are not eating.
The blood contains amino acids at all times. Fasting does not clear them, and a high protein diet does not materially increase them. The body has a constant need for protein amino acids, and it keeps a fairly uniform balance.
LIPIDSfats and fatlike compounds, characterized by their insolubility in water
METABOLISM OF FATSThe Ultimate Fuel Source
Triglycerides (stored fats): glycerol and 3 fatty acid chains
• There is a carboxylic acid group on the end of each fatty acid chain
• The longer the chain and the smaller number of double bonds, the lower the fluidity state
Fat Chemistry
Fats are the ideal substance for storing energy because per unit weight they occupy less volume and produce more ATP than carbohydrates and protein.
• 60% of the energy requirement of the heart, under basal condition, is derived from fat
Fat as an Energy Source
Glycerol can be liberated by the breakdown of triglycerides(lipolysis) in the liver and fat cells.
• Glycerol molecules can be recombined to form glucose through glycogenesis (reverse glycolysis)
• Fatty acids can also be converted into some amino acids and are then used to make proteins.
The Role of the Liver
FATS LIPID MOLECULES COMPOSED OF:
•Glycerol: 3 carbon skeleton with 3 alcohol groups
•3 fatty acids: carbon skeleton with a carboxylic acid group on one end
PHOSPHOLIPID
contains a glycerol and fatty acids like a fat molecule but the 3rd fatty acid is replaced by a phosphate group
SATURATED FATTY ACIDcontains a carbon skeleton with no double bonds
Unsaturated Fatty Acid contains a carbon skeleton with at least
one double bond
Bonding of lipids is a dehydration synthesis reaction
Glycerol liberated by the breakdown of lipids can be recombined to form glucose.
Unemulsified Fats
Bile Saltsproduced by the liver
Pancreatic Lipase (small intestine)
Monoglycerides Glycerol & Fatty Acids