[2] Class 5- Theisen Fundametal Of Nutrition Flashcards
What form(s) of metabolism occur(s) in the cytosol?
Glycolysis
Pentose phosphate pathway
Fatty acid synthesis
What form(s) of metabolism occur(s) in the mitochondrial matrix?
TCA
Oxidative phosphorylation
ß-oxidation of FAs
Ketone body formation
What form(s) of metabolism occur(s) in the interplay between both cytosol and mitochondrial matrix:
Gluconeogenesis
Urea synthesis
7 forms of metabolism:
Glycolysis Gluconeogenesis Glycogen metabolism FA metabolism Citric acid cycle Oxidative phosphorylation AA metabolism
What organ can carry out all of the reactions in the major pathways?
Liver
3 key points in metabolism:
Glucose-6-phosphate
Pyruvate
Acetyl-CoA
3 major elements of energy in body/foodstuff?
Sugars, proteins, lipids
What dictates insulin/glucagon response or BG detection?
Liver
Central component to all of metabolism
Carbon
Carbohydrates and protein are both 4 kcal/g. So, if you eat the same amount, there is no difference in energy consumed, right?
No, there is a difference because of the different pathways the food req’s for breakdown..different amt’s of energy are required to break down either
In what form does the body provide energy for the metabolism [breaking down] and catabolism [forming] of biomolecules?
In the form of ATP
Biomolecules built from AA’s
Critically important in cell life
Proteins
3 functions of proteins:
Fuel supply[TCA cycle->ATP production]
Structural support [elastin,keratin]
Activity[enzymes]
Where can several AA’s be found in metabolism
As intermediates
Nitrogen-containing carboxylic acids
Proteinogenic AAs Serve as basic building blocks of peptides and proteins
AA function as precursors of biologically important molecules:
-acetyl CoA, heme, melanin, amines, hormones(insulin/glucagon)
Amino acids
What kind of amino acids are required for maintaining health?
Essential AA’s
What is an effect of not consuming enough essential AA’s?
Negative nitrogen balance
Organic molecules
Made up of C,H,O (3-9C[H2O])
Important fuel stores
Critical molecules control of human metabolism- catabolic
Carbon skeletons used for synthesis of the other important biomolecules-anabolic
Carbohydrates
4 common dietary carbohydrates:
Starch
Sucrose
Dietary fiber
Lactose
The nutritional reservoir in CH of plants
Polysaccharide of glucose
Amylose and amylopectin
Starch
The unbranched glucose polysaccharide in plants
Amylose
The branched glucose polysaccharide in plants
Amylopectin
The natural sweetener and found in fruits and vegetables
Disaccharide of glucose and fructose
Sucrose
Plant origin carbohydrate
Dietary fiber
The major dietary carbohydrates of animal origin
Disaccharide of glucose and galactose
Lactose
This condition is d.t the body’s inability to easily digest lactose [gas,belly pain, bloating]
Lactose intolerance
Simplest form of carbohydrates?
Monosaccharides
Ex of monosaccharide:
Glucose, fructose, galactose, ribose
Two monosaccharides:
Disaccharide
Ex of disaccharides:
Maltose, lactose, sucrose
3-10 monosaccharides
Oligosaccharide
Ex of oligosaccharide:
Glycolipids and glycoproteins
> 10 monosaccharides
Polysaccharides
Ex of polysaccharides:
Glycogen, starch, cellulose
Diastereomers that differ in configuration of only one stereogenic (chiral) center
Epimers
What is more stable open-chain or ring structure?
Ring structure
Monosaccharides exist in sol’n mainly as _____ structure?
Ring
How are glycosidic bonds formed?
By the hydrolysis of starch
A polysaccharide of glucose residues linked w/ a alpha 1,4 glycosidic bond
Starch amylose
Amylose w/ addition of alpha-1,6 glycosidic branch
Amylopectin
Major plant polysaccharide
Unbranded polymer of glucose residues joined by ß-1,4 linkages, allowing to form very long and straight chains
Cellulose
Why does cellulose/starch and glycogen favor bent structure ?
More suitable for storage
Major component of DNA
Deoxyaldose
Components of glycoproteins and glycolipids
Important in cell signaling, adhesion
Acetylated Amino sugars
Glycosaminoglycans and proteoglycans. Present in cell membrane and in ECM
Acidic sugars
Constituted the gangliosides in oligodendrocytes of NS
Sugar esters
Food additives, gains importance in uncontrolled diabetes leading to cataracts and peripheral neuropathy; used in synthesis of lipids
Sugar alcohols
Why is high fructose corn syrup so fattening?
It bypasses a major regulatory step in glycolysis, entering at step 5 [DHAP=easily converted to glycerol-becomes fat easily] This disrupts fuel metabolism and increases productions of lipids since DAG can be converted to glycerol-3-phosphate and then into triacylglycerols
What is the catch w/ the glycemic index?
I only measures BG levels and b/c it is low in glucose doesnt mean it is low in kcal
Are artificial sweeteners on Glycemic index?
Yes and theyre > 0
What can stimulate insulin release
Modified sugar alcohols
What’s the good sweetener?
Stevia 0 kcal and natural sugar
Water insoluble biomolecules that’re highly soluble in organic solvents
Membrane constituents
FA are key constituents
Lipids
_________ properties of lipids are d/t the FAs
Hydrophobic
What contributes hydrophobic properties f lipid?
FAs
What’re building blocks of phospholipids and glycolipids, components of biological membranes?
FAs
What type of FA have highest energy?
Saturated FA
Critical enzyme for lipid digestion
Lipase
Where are FA oxidized to generate ATP?
Mitochondria
FA oxidized or reduced?
Oxidized
EFAs?
Linoleic acid
Linolenic acid
Arachidonic acid `
Why is it called EFA?
Our body cant produce it
Introduction of a double bond in FA ________ potential energy
Reduces
How are trans fats metabolized?
They aren’t able to be metabolized. They increase cholesterol because the body can only metabolize Cis fats
Digests short and medium chain FAs in oral cavity:
Lingual lipase
Digest short and medium chain FAs in gastric cavity:
Gastric lipase
Digest triacylglycerols in small intestine
Pancreatic lipase w/ colipase
Digests phospholipids in small intestine
Phospholipase
Digest cholesterol esters in small intestine
Cholesterol esterase
Fatty acid derived vitamins:
A,D,E,K
FA dervied vitamins can be important in:
Signaling
Cholecalciferol
Vitamin D3
What is the bioactive form of Vit D and is derived from vit D2 and D3?
Calcitriol
How id Vit D produced?
Exposure of UV light on skin
Where is Vit K1 obtained from?
Leafy green vegetables
Vitamin K2 is synthesized by
bacteria in the large intestine and colon
Vit D is ______-derived
Cholesterol
2 ways Vit D is produced:
In the intestine and in the skin by UV exp.
Liver makes _______ and kidney makes the active for _______
Calciferol; calcitriol
Scientific name for calcitriol
1,25-dihydroxycholecalciferol
Vit D intestinal rxn:
Ergocalciferol (D2)
Cholecalciferol (D3)
Skin precursor to cholecalciferol (D3)
7-dehydrocholesterol
When cholecalciferol (D3) in either skin or intestine, where does it travel? What does it become?
Liver;
25-hydroxycholecaliferol
What is the enzyme in the liver that converts cholecalciferol to 25-hydroxycholecalciferol?
25-hydroxylase
After rxn in liver by 25-hydroxylase, where does resulting 25-hydroxycholecalciferol travel? What is produced? By what enzyme,?
Kidney;
1,25-dihydroxycholecalciferol [calcitriol];
1-alpha-hydroxylase
Regulation of calcitriol [active vit D] +/-?
+: PTH
-: calcitriol
What is asso. W/ vit k?
Blood clotting
What enzyme asso w/ vit k is asso. W/ clotting?
Gamma-carboxylase
What is vit k function w/gamma-carboxylase?
Cofactor for clotting
How does warfarin function?
Inhibits gamma carboxylase by inhibiting its cofactor (vit k) `
What is req’d for coagulation in gamma carboxylase rxn ?
CO2
O2
Vit K hydroquinione (active)
Why do energy drinks and vitamins boost energy?
They provide substances that fit into TCA cycle- increase action of cellular respiration
Req’d minerals in diet:
Na+,K+,Cl- electrolyte
Ca+, P, Mag, Fe, S mineral
I,Se,Cu,Zn. Trace mineral
Mn,F,Cr, Mo ultratrace mineral
Why do low vitamins/minerals affect activity?
Theyre req’d for certain molecular processes by the proteins/enzymes that complete the processes
Small organic molecules often derived from vitamins, what’re they called when tightly bound?
Coenzymes ; prosthetic groups
Oxidation state of Fe when being transported in circulation:
3+, b/c it wants to be unrecognizable and not uptaken by any tissue/cell until destination is found
Oxidation state of Fe when entering in cell/tissue from circulation:
2+, this is recognizable for cells/tissues
Transport molecule for Fe
Transferrin q
Specific Fe pore:
Ferroportin
In order to enter cell Fe3+ must become Fe2+. This occurs by what enzyme? What vitamin is req’d for this enzyme to function?
Ferric reductase;
Vitamin C
Energy req’d to maintain life:
basal metabolic rate (BMR)
A linked series of chemical reacitons that begins w/ a particular molecule and converts it into some other molecules or molecules in a carefully defined fashion
Metabolism
Which enzymes predominant in the interdependent metabolism pathways coordinated by sensitive means of communication?
Allosteric
Those that convert energy from fuels into biologically useful forms
Catabolic
Those that req’ inputs of energy tp proceed
Anabolic
Universal currency of free energy
ATP
Which bond of ATP is most labile
Gamma
What is the significance of ATP ?
High energy bonds
An important form of cellular energy transformation
Phosphoryl-transfer potential
Serves as the principal immediate donor of free energy
ATP
ATP molecule is consumed within a _______ of its formation
Minute
Total quantity of ATP in the body is limited to
100 g
Turnover of small ATP quantity [100 g]:
Is very high
Human ATP consumption in 24 hours
40 kg
Strenuous exertion of ATP may be as high as ____kg/min
0.5
Important source of cellular energy
Oxidation of carbon fuels
Having mechanisms for regeneration of ATP=
Vital
Activities that req’ ATP:
Motion, active transport, signal amplification, and biosynthesis
One of the primary roles of catabolism
Generation of ATP
Fuel molecules composed of carbon are oxidized to
CO2, resulting e-are captured and used to regenerate ATP from ADP
How many kcal/g in alcohol
7 kcal/g
Crucial for maintaining health:
Essential AA
What happens if inadequate diet of Essential AA:
Negative nitrogen balance
Why are there EFA?
We cant make the cis bond. that’s why there’s no way to digest…
Fat-soluble vitamins cant be absorbed if:
there’s is a bile/emulsification error
Where does vit d become activated?
Kidney
What hormone would increase activation of Vit D?
PTH and low PO4
Function of Vit D?
Reabsorption of Ca+
Important serve of energy
Oxidation of carbon fuels
Ultimate electron acceptor
O2
Oxidation product
CO2
Saturated=
Reduced and more PE!
How does the oxidation of carbon take place?
When a fuel is oxidized, the oxidation takes place one carbon at a time
Potential energy in saturated vs. polyunsaturated
Saturated has more potential energy
Carbon-oxidation energy cen be used to create ion gradients or
High phosphoryl-transfer potential —-both endpoints = ATP
Bond is broken and immediate energy=
Redox or ADP
Energy from foodstuffs is extracted in how many stages?
3
Stage I:
degradation and absorption
Stage II
Sugars and FAs converted to acetyl CoA-some ATP produced
Stage III
Aerobic respiration- most ATP made
Metabolic processes are regulated 3 principal ways, by controlling:
Amt.’s of enzymes
Catalytic activity
The accessibility of substrates
