1 food /exercise diary or essay option-questions? -if consuming the recommended number of servings...
TRANSCRIPT
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Food /exercise diary or essay option-questions? -if consuming the recommended number of servings for each food group for one’s
age and gender one is most likely meeting all of one’s dietary nutrient requirements.
-hence no worries about consuming foods without a food label
No discussion of pathology in the 2104 essay option- any questions on essay or dietary assessmentoption?
94/80AA displacement
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LECTURE 6A PROTEINS
9 Feb. 2015
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a) Proteins defined p. 168
contain carbohydrate, hydrogen and oxygen just like lipids and carbohydrates
but proteins also have nitrogen
shape and hence function depends on amino acid side chains
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Amino acids P. 168-9
Amino definition Building blocks
Non-essential
Essential
Conditionally essential
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Protein structure p. 169-170
considerable variety of proteins
variety comes from lots of different shapes and hence functions of protein
loss of shape-loss of function heat, acid, beating, chemically (e.g. urea)
get easier digestion and occasionally colour change
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IDATME of proteins and amino acidsP. 171-172
Ingestion - oral, tube (whole protein, or protein hydrosylates or amino acids), IV (amino acids only)
Digestion•Stomach-acid and pepsin•Small intestine lumen-oligopeptides,tri- and
dipeptides, and amino acids formed•Small intestine wall-tri- and dipeptides formed
into single amino acids•Issues of dietary enzymes and pre-digested proteins
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IDATME of proteins and amino acidsP. 171-172
Digestion
https://www.youtube.com/watch?v=laNhqcMEAHY
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IDATME of proteins and amino acids continuedAnimal proteins are generally very digestible and plant proteins are generally less digestible than animal proteins
Proteins vary in their digestibility due to variable dietary protein structures as well as other food ingredients and hence accessibility to protein digestive enzyme active sites
Complete plant proteins -soy - very digestible - close to many animal proteins’
digestibility -quinoa - about 10 % less digestible than soy
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IDATME of proteins and amino acids continued
Digestibility affects availability (WWFQ) of essential and non-essential and conditionally essential amino acids
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IDATME of proteins and amino acids continued
Absorption P. 185
Carriers
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Transport Blood-amino acids alone
or as part of proteins
IDATME of proteins and amino acids continued
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PROTEIN METABOLISM
DNA to PROTEIN P. 173-175
E:\Media\Animations\chapter6\Protein_Synthesis\0606.html
Fig. 6-7, p. 188
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PROTEIN METABOLISM
Proteins broken down to amino acids and amino acids then broken down to urea and water
Also have synthesis of non-essential amino acids in the body
Essential and non-essential amino acids and conditionally essential amino acids are made into proteins
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PROTEIN EXCRETION
Faeces- undigested protein and unabsorbed amino acids
Urine- urea and water
Sweat- metabolic water formed by amino acid catabolism
Respiration- CO2 and water from amino acid
catabolism
Saliva?-whole proteins
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STRUCTURE IN THE BODY PrimarySecondaryTertiaryQuaternary Globular Fibrous Undone - heat, chemically, mechanically, pH
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PROTEINS ESSENTIAL OR NOT?
Yes- functions
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PROTEIN FUNCTIONS P. 175-178
CHAPERONES
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PROTEIN FUNCTIONS CONTINUED
ENZYMES
proteasescarbohydraseslipases
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PROTEIN FUNCTIONS CONTINUED
NUTRIENT AND STORAGE PROTEINS
nutrient proteinsovalbumincasein
storage proteinsferritin
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PROTEIN FUNCTIONS CONTINUED
TRANSPORT PROTEINS
lipoproteinshemoglobinglucose transportersamino acid transporters
sodium potassium transporter
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PROTEIN FUNCTIONS CONTINUED
CONTRACTILE OR MOTILE PROTEINS
actinmyosin
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PROTEIN FUNCTIONS CONTINUED
STRUCTURAL PROTEINS
collagenelastinkeratin
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PROTEIN FUNCTIONS CONTINUED
DEFENCE PROTEINS
antibodiesfibrinogenthrombin
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PROTEIN FUNCTIONS CONTINUED
REGULATORY PROTEINS
insulinparathyroid hormone
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PROTEIN FUNCTIONS CONTINUED
RECEPTOR PROTEINS
insulinLDL receptor
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PROTEIN FUNCTIONS CONTINUED
SIGNALLING PROTEINS
insulin sets off signalling cascade forglycogen synthesis
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PROTEIN FUNCTIONS CONTINUED
Energy
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In summary proteins:
•Bind (B)
•Catalyse (C) •Build (B)
PROTEIN FUNCTIONS CONTINUED