Class notes
Lecture 1 Nutritional Physiology
- Course
- Institution
- Book
Lecture 1 Nutritional Physiology: digestive system, what happens during digestion at the different organs, segmentation
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
NP18 & NP19: Lectures 18 and 19 Nutritional Physiology + practice exam questions
-
NP15, 16 & 17 - Lectures 15, 16 and 17 Nutritional Physiology + exam questions about proteins NP15 – Thermoregulation: how to use the heat diagram and partitioning of ME NP16 – Protein metaboli...
-
NP13 & NP14 Lectures 13 & 14 Nutritional Physiology NP13 – Heat balance: constancy of body temperature NP14 – Heat diagram: how is body temperature maintained? = thermogenesis
Seller
Follow
louise_s
Reviews received
Content preview
NP01- Mass flow of nutrients (through the body and its cells)3 balancing aspects in nutritional physiology – in balance
Post-absorptive phase: in the morning when you get up: you rely on the energy in your body
The metabolism is constantly switching in pathways and energetic efficiencies à might affect body composition
Nutritional input Physiological input: Metabolism
- Total daily intake (kJ) - physiological status - different metabolic pathways
- meal size, pattern - health status - different energetic efficiencies (do
- nutrient composition - environment you need more heat or more energy)
= whatever you eat - If start to exercise à need more energy - different body composition – waste
- If you’re really old à need also energy products
Dietary components – nutrients:
Macronutrients bring the energy: carbohydrates, proteins, fat
They moved through the body via:
§ Translocation (from different positions) AND
§ Transformation (adapted and broken down in different structures: ultimately into monomers so they
can be absorbed in the GI tract)
à regulated by the neural system and the endocrine system (hormones)
How do nutrients leave the body? à via the lungs as CO2. The majority of the nutrients are being oxidized (to
provide energy to the body) and they are producing CO2 when oxidized à so they are exhaled
à big difference between what you eat (nutrients) and what you exhale (CO2)
What happens after eating?
We hardly have any influence on the fate of food after swallowing it. You can’t determine with your mind what
you’re going to do with the food. Increasing interest in feeding strategies aimed to influence the fate of food.
§ Digestion and absorption
§ Storage (TAGs in adipose tissues, glycogen in muscles and liver)
§ Utilisation (used and oxidized, or proteins converted into carbs and vice versa)
1. Digestion <-> Fermentation
Microbial fermentation may provide energy but NO amino acids
Meal is coming in the GI tract à bolus is broken down in smaller particles (macromolecules)
With the addition of enzymes and lots of water, ions and bile acids (for lipids): we get monomers/oligomers
which can be absorbed à transported in the blood to the body where it can be used for energy or stored
2. Enzymes lower the activation energy (e.g. proteolytic enzymes)
In non-enzymic reaction: lots of energy is needed/should be invested to get the final product (requires extreme
conditions and lots of energy is needed)
With enzymes: we only need a fraction of the required energy to reach the final product and lower
temperature: one enzyme with specific amino acids: very specific and target one specific reaction
à proteolytic enzymes make sure specific bonds are hydrolysed by lowering activation energy of proteolysis
3. Why does the digestive system doesn’t digest itself?
• The activity of enzymes is restricted to presence of food. E.g. no release of enzymes when you’re
sleeping à regulation (locally, distal, proximal) when the food is there or not
• Pro-enzymes (= zymogens = not activated yet): not functional yet, so they are in the cells available to
digest food components.
• Mucus = protective layer/barrier coating the walls to avoid digestion of the walls by the enzymes
• High replacement rate (turnover) of mucosal cells lining the intestine
à all these have an influence on metabolic settings: how well are you digesting food and energy
Settings of metabolism
We start with digestion and absorption of monomers after having eaten the food
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller louise_s. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.25. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75323 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now