nutrition 🍗 Flashcards
what is the role of protein
help to repair and build tissues
what is the structure of protein
complex organic compounds made up of carbon, hydrogen and oxygen, they contain nitrogen and sulphur. they are composed of long amino acids which can be essential aa or non-essential aa.
list types of essential aa
arginine, histidine, isoleucine, leucine, lysine, taurine, valine
list functions of proteins
- growth
- repair of damaged tissues
- increase milk production in lactation
- supports growth in pregnancy
- source of energy
- regulation of metabolism
- part of the structure of cell walls and muscle fibres
- provides strength with flexibility in ligamaments, tendons and cartilage
- transports and stores o2 in the muscles as myoglobin
- transports other nutrients
- protection of the body against infections
what 4 organs are used in digestion of protein
mouth, stomach, SI, liver
how is protein digested in the mouth
mechanical digestion starts with mastication
how is protein digested in the stomach
mechanical and physcial breakdown continues, chemical digestion starts. the chief cells secrete pepsinogen which becomes active pepsin in the presence of HCA which is secreted by parietal cells.
protein break down into polypeptides by pepsin. renin will start to coagulate milk proteins.
how is protein digested in the SI
enterokinase from the intestine acts on trypsinogen produced by the pancreas to form active trypsin.
trypsin breaks down peptides into other proteins and aa. peptidases break down polypeptides into free aa. blood flows from SI to liver via hepatic portal vein
how are aa absorbed
through the intestinal wall into the blood
how is protein digested in the liver
synthesis of tissue proteins and enzymes such as albumin and hormones by aa. the surplus protein is used as energy
how is protein utilised
for growth and repair and energy
what is the role of fat in the body
to store energy and regulate body temp
what is the structure of fat
dietary fats is part of a group called lipids.
what are lipids
lipids are termed fats when solid at room temp and oils when liquid at room temp.
what is the most common form of dietary fats
triglycerides
what are triglycerides composed of
one molecule of glycerol and 3 molecules of fatty acids.
what determines physical and nutritional characteristics of fat
specific types of fatty acids
functions of dietary fat
- provision and storage of energy
- essential fatty acids
- aid abroption of fat soluble-vitamins ADEK
- metabolic and structural functions
- insulation
- enhance food palatability
- synthesis of hormones
what organs are used to digest fat
mouth, stomach, SI, bile, liver
how is fat digested in the mouth
mechanical digestion by mastication. lingual lipase hydrolyses and breakdowns lipids
how is fat digested in the stomach
a lipid is in the structure of a triglyceride which is 3 fatty acids and a glycerol. bile salts in the stomach will emulsify the lipds which coats them for the digestion of the enzyme gastric lipase to break down fats to fatty acids and monoglycerides with the help from micelles which is a ball composed of broken down parts of fat which are composed of bile salts, fatty acids, monoglycerides and cholesterol. the fat droplets and the acidity of the stomach stimulate the SI cells to produce secretin which stimulates the bicarbonate secretion to raise the intraluminal ph to 6.5 which is the optimum ph for fat digestion and cholysistokinen which stimulates pancreatic juice and bile production and secretion
how is fat digested in the SI
monoglycerides and fatty acids are transported and absorbed in the jejunum. bile breaks down the fat into droplets by breaking down the surface tension so lipase can breakdown the fat. bile salts remain in the lumen as they arent reabsorbed here. they reach the ileum fir active reabsoroption and enter the HPS and travel to the liver. fats are absorbed into the lymphatic system by the lacteals and pass into the cyterna chyli and then into the lymphatic duct into the blood supply which is then carried to the liver to be converted and used for energy production, however some fat is utilized immediately to release energy and some is stored in adipose tissue.
how is fat digested in the liver
fat metabolism takes place. the lipds required by the body are synthesised in the liver and fatty acids are metablosised to produce energy. fatty acids enter cells and must reach the mitochondira in order to be useful. L. carnitine helps to transport fatty acids into the mitochondira so they are used for energy. bile salts are recycled and created into bile to be used again.
what can fat also provide structure-wise
essential fatty acids including linoleic acid and arachidonic acid.
what are the functions of linoleic acid and arachidonic acid
- acting as constituents of cell membranes in prostaglandin synthesis during inflammation
- control of water loss through the skin
what is the role of water
- metabolic processes
- chemical reactions
- temperature regulation
- eliminating waste from the body
- health and survival.
what is the structure of water
one oxygen atom bonded to two different hydrogen atoms
what is the function of water
- transports medium
- temperature regulation
- digestion
- lubricant
- elimination
- hydrolysis
how is water utilised in the body
- helps different digestives juices and food components interact
- enhancing digestion
- excretion of waste products in the form of urine, faeces, and perspiration, sweat,
how is water absorbed in the body
water absorption occurs in the small intestine with additional absorption in the large intestine
what is the structure of carbohydrates
composed of hydrogen, carbon and oxygen. CH20
what is the function of carbs
- provision of energy
- synthesis of body compounds- RNA and DNA
- source of fibre
what can carbs be classed as
monosacchardies
disaccharides
polysaccharides
what organs are involved with carb digestion
mouth, stomach, liver and SI
how are carbs digested in the mouth
pytalin is secreted by the parotid gland and salivary amylase starts the digestion of carbs
how are carbs digested in the stomach
some mechanical digetsion occurs. enzymatic digestion also occurs as the low ph of the stomach inactivated salivary amylase
how are carbs digested in the SI
pancreatic amylase is released which breaks down the digestion of starch or glucose. on the brush border of microvilli are enzymes that finish the breakdown of carbs into single glucose molecules that can be absorbed. the carb molecules are now broken down into disaccharides, sucrose, maltose and lactose. disaccharides break down into monosaccharides as monosaccharides are the only carb that can be broken down. maltase breaks down maltose into glucose, surcase breaks down sucrose into glucose and fructose, lactase breaks down lactose into glucose and galactose.
how are carbs digested in the liver
Glucose etc. is absorbed into the blood stream and carried via the hepatic portal vein to the liver where it is stored and glycogen and release into the circulation as required for energy.
how is fibre digested
Fermentation i.e. carbohydrates broken down in an environment with little or no oxygen in such a way as to release energy. Microbes in the LI are anaerobes (i.e.no oxygen)
Microbes only use part of the energy they release the rest can benefit the mucosal lining of the large intestine.
Some fibres are more rapidly fermented than others. The more rapid the fermentation the more gases and short chain fatty acids are released in a short time i.e. the more flatulent they are!!
what are the functions of energy
walking
running
repair
growth
what are the nutrients that supply energy
fats
carbs
protein
how does the body obtain energy
oxidising the food is eaten
what regulates the rate of which energy is released
enzymes
what is gross energy
total energy released by the oxidation of food in an environment of pure oxygen
what is gross energy measured by
bomb calorimetry
what is digestible energy
energy available from a food when its been absorbed into the body after digestion in the digestive tract
how is digestible energy calculated
gross energy minus faecal losses
what metabolisable energy
the energy that is ultimately utilised by the tissues
how metabolisable energy calculated
digested energy minus urinary losses
what is net energy
the energy to an animal for the upkeep of vital functions, exercise, growth and adaption to changing environments etc
how is net energy calculated
metabolisable energy minus heat increment
how much does fat provide in energy
8.5kcal/g
how much does protein provide in energy
3.5kcal/g
how much does carbohydrates provide in energy
3.5kcal/g
what is basal metabolic rate or basal energy expenditure
the energy required to keep essential bodily processes functioning and so maintain the animal
what is resting energy rate
the energy required by an animal in a thermo-neutral environment 12hrs after eating
what is the decimal for RER with a neutered animal
1.6
what is the decimal for RER with light exercise
2.0
what is the decimal for RER with an obese animal
1.4
what is the decimal for RER with a lactating animal
1.9 x RER + 25% for each puppy
what is a complete diet
nutritionally balanced when fed alone
can be in any form
composition must meet the nutritional requirements of the stated species at the particular life stage its sold for
what is a non-conplete diet
not balanced when fed alone
can be in any form
an additional diet which should be fed
should clearly state the life stage and purpose of diet
what is proximate analysis
method of determining the analytical consituents