Session 1 Flashcards
What is exergonic?
Releases more energy than is used
What is the BMR, and it’s function?
Basal Metabolic Rate. Maintains the resting activities of the body by
- maintenance of cells and ionic transport
- functions of organs
- body temp
What is endogonic?
Releases less energy than is used
Where is creatine phosphate found?
In the muscles
What are dextrins?
The carbohydrates produced when starch/glycogen is hydrolysed. They are oligosaccharides, hence 3-12 units.
What are the different types of carbohydrates?
Mono, di, oligo and polysaccharides
What is glycogen and where is it found?
Animal storage of alpha glucose.
Found in the liver and skeletal muscle.
Very branched, containing lots of glucose.
Normal alpha 1->4 glycosidic bonds, and branched alpha 1->6 glycosidic bonds
What is starch hydrolysed to by GI enzymes, eg amylose?
Alpha glucose and maltose
What is starch?
Plant store of alpha glucose
Mixture of amylose (a1-4) and amylopectin (A1-4 & a1-6)
Less branched than glycogen
What is cellulose otherwise known as?
Fibre, healthy GI function
What digestive enzyme is found in the saliva?
Amylase converting starch & glycogen into its dextrins
What enzyme and function found in pancreas?
Amylase converts dextrins into monosaccharides
What enzymes are found in the small intestine?
Lactase Sucrase Pancreatic amylase (breaking a1-4) Isomaltase (a1-6) Hydrolysed the disaccharides that attach to the micro villi of epithelial cells
How is carbohydrates uptaken by cells?
Facilitated diffusion by TRANSPORT PROTEINS GLUT1-5
Or hormones, insulin uses GLUT-4
Different GLUTS have different distribution and affinities.
What form do carbohydrates exist?
Asymmetric Carbon, therefore in D (natural form) or L form.
Monosaccharide exist as ring structures, how?
Aldehyde/ketone group react with alcohol group in same sugar to form a HEMIACETAL RING
Anabolism is activated by…?
High ATP
Catabolism is activated by…?
Low ATP & High ADP/AMP
Carrier components contain…?
Components from vitamins
What is creatine phosphate?
Creatine + ATP –> Creatine Phosphate + ADP
Via CREATINE KINASE
High energy immediate reserve.
High ATP increases synthesis of CrP
What is PEP?
Phospoenolpyruvate
Contains high energy phosphate bonds
Why are phosphate compounds useful?
Phosphate-phosphate bonds have high energy, hence high energy of hydrolysis.
Eg, ATP, CrP and PEP
What happens if the energy intake is insufficient?
The body utilised energy stores for a continuous supply of energy
What is cell metabolism?
Highly integrated network of chemical reactions within a cell
What does cell metabolism produce?
- energy for cell function
- building blocks for repair, cell division, growth and maintenance
- organic precursors, inter conversion of building block molecules eg Acety- CoA
- biosynthetic reducing powers eg NADPH
What is homeostasis?
Maintenon of stable internal environment & dynamic equilibrium
Eg, nutrients, blood flow, body temp, waste removal, CO2 & pH
How is body weight determined?
Difference between:
Imput - (output of substance + energy from body)
What is obesity?
Excess body fat that accumulates and may have adverse effects of health.
BMI > 30
What are the diet essentials?
Carbs Proteins Fats Vitamins Water Fibre
How much energy is in carbohydrates?
17kj/g
What are fats used for?
Energy storage
Fat soluble vitamins eg Vitamins ADEK
What are proteins used for?
Source of Essential AAs Nucleotides Heam Creatine - growth and repair
What is BMI?
Body Mass Index.
BMI = Weight (kg) / (Height (metres))squared
BMI <18.5
Underweight
BMI = 18.5-24.9
Desired BMI
BMI = 25 -29.9
Overweight
BMI = 30-34.9
Obese
BMI > 35
Severely Obese
What is the daily energy expenditure comprised of?
- BMR
- energy for voluntary physical activities
Energy required to process food we eat (diet-induced thermogenesis)
Major tissues that contribute to BMR?
Skeletal muscle 30%
CNS 20%
Liver 20%
Heart 10%
How does hyperthyroidism, lactation and pregnancy affect BMR?
Increases BMR
Calculating Daily Energy Expenditure?
Sum of BMR + energy required for amount of time spent in different types of physical activities + 10% (due to diet-induced thermogenesis by food digestion)
Energy content of fat?
37kj/g
Energy content of proteins?
17kj/g
Why are fats important in the diet?
- Source of linoleic and linolenic acids - precursors to EICOSANOIDS
- Energy yield of 2.2 times greater than carbs and proteins
- Absorption of fat soluble proteins, lack of fat leads to vitamin deficiency
What is zero nitrogen balance?
N2 intake = N2 loss
Adult male hence must consumer 35g of protein
What type of Nitrogen balance do growing children and pregnant women show?
Positive N2 balance as N2 intake>N2 loss
When does Negative N2 Balance occur?
Starvation and tissue wasting diseases as high loss of Nitrogen
What is Marsmus?
Protein energy malnutrition as individual lacks everything!
Signs of Marasmus?
NO ODEMA as muscle protein are hydrolysed for energy production hence sufficient plasma protein
Bradycardia Emancipated Lack of body fat Muscle wasting Thin hair/loss Diarrhoea Maybe aneamia
Pathophysiology of Marasmus?
Love glucose and low glycogen
Hence lipogenesis produces keto bodies to supply brain & RBC
Ketoacidosis if large and fatal changes to blood pH
What is Kwashikor?
Normal carbohydrate consumption but LOW protein diet
Eg, during breastfeeding
What is cellulose and what is unique?
Plant cell wall comprised of BETA glucose.
Structural with strong and stable B1->4 glycosidic bonds.
There are no GI enzymes able to digest cellulose.
Signs of Kwashikor?
K-washikor
O-dema low serum albumin low onocotic pressure
Sufficient energy therefore no proteolysis
A- pathy
L- ethargy
A- norexia - lack of appetite and aneamia
Heptomegaly - enlarged and fatty liver as lack of proteins to take TAGs out
Hepatospleemagaly - enlarged liver + spleen due to high RBC breakdown
Visible rib cage
Ascites - accumulation of fluid in peritoneal cavity
