Lecture notes

IB Biology Option D: Human Physiology Notes + Detailed Guide

1 purchase

Module
IB Biology Option D

Institution
Truro And Penwith College

THIS IS A DIGITAL PRODUCT SO NO ITEMS WILL BE SHIPPED ───── What is Included? ───── This digital download will give you 40+ pages of very detailed study notes for standard level IB Biology! This detailed guide helped me get a level 7. The topics included are: - Hu...

[Show more]

Preview 4 out of 46 pages

View example

Uploaded on June 11, 2021
Number of pages 46
Written in 2020/2021
Type Lecture notes
Professor(s) Mm
Contains All classes

ib biology
ib sl biology
ib biology option d
option d
biology option d
human physiology notes
human p
ib
international baccalaureate
international baccalaureate bio
international baccalaureate biology

£10.99

Add to cart

Save

100% satisfaction guarantee
Immediately available after payment
Both online and in PDF
No strings attached

©️StudyWithKiki on Etsy
IB BIOLOGY:
Option D - Human Physiology

These notes are designed to help you with paper 3, the extra option
paper!

These notes include the following topics:
- Human Nutrition
- Digestion
- Function of the Liver
- The Heart
- Hormones and Metabolism

,©️StudyWithKiki on Etsy
Topic 1: Human Nutrition

Outline why nutrients cannot be synthesised by the body, and why they have
to be included in the diet
● A nutrient is a chemical substance found in foods that is used in the
human body.
● There are six classes of nutrients – carbohydrates, proteins, lipids,
vitamins, minerals and water.
● Essential nutrients are those that cannot be synthesised by the body
and must be ingested as part of the diet.
● Non-essential nutrients can be made by the body or have a replacement
nutrient which serves the same dietary purpose. Carbohydrates are not
considered essential nutrients as human diets can obtain energy from
other sources without ill effect.

Describe how malnutrition may be caused by a deficiency, imbalance or
excess of nutrients in the diet
● Malnutrition is a health condition caused by a deficiency, imbalance or
excess of nutrients in the diet.
● It can be caused by an improper dietary intake of nutrients – e.g.
overnutrition (too much) or undernutrition (not enough). It can be
caused by the inadequate utilisation of nutrients by the body – e.g. due
to illness or disease.
● The symptoms of malnutrition will vary according to the specific nutrient
and the type of imbalance involved. Common signs of malnutrition
included stunted growth and wasting (undernutrition), as well as obesity
(over nutrition).

Determine the energy content of food by
combustion
● The energy content of food can be
estimated by burning a sample of known
mass and measuring the energy released
via calorimetry.
● Combustion of the food source causes the
stored energy to be released as heat,
which raises the temperature of water.
The amount of energy required to raise 1 g

,©️StudyWithKiki on Etsy
of water by 1ºC is4.18 J – this is the specific heat capacity of water.
● The equation for calculating the energy content of a food source via
calorimetry is as follows:
○ Energy (joules) = Mass of water (g) × 4.2 (J/gºC) × Temperature
increase (ºC)
● The biggest source of error in calorimetry is usually caused by the
unwanted loss of heat to the surrounding environment.
● The food sources should be burnt at a constant distance from the water
to ensure reliability of results.
● The initial temperature and volume of water should also be kept
constant (1 g of water = 1 cm3 or 1 ml).

Comparing Energy Content
● The three types of nutrients that are
commonly used as energy sources are
carbohydrates, lipids (fats) and
proteins.
○ Carbohydrates are
preferentially used as an
energy source because they
are easier to digest and
transport
○ Lipids can store more energy
per gram but are harder to
digest and transport (hence
are used for long-term
storage)
○ Protein metabolism produces nitrogenous waste products which
must be removed from cells
● The relative energy content of carbohydrates, proteins and fats are as
follows:
- Carbohydrates – 1,760 kJ per 100 grams
- Proteins – 1,720 kJ per 100 grams
- Fats – 4,000 kJ per 100 grams

, ©️StudyWithKiki on Etsy
Amino Acids and Lipids

Explain why some amino acids are essential and how a lack of essential
amino acids affects the production of proteins
● Amino acids are the monomeric building blocks from which proteins are
constructed.
● There are 20 different amino acids which are universal to all living
organisms.
● Amino acids can be either essential, non-essential or conditionally
non-essential according to dietary requirements.
● Essential amino acids cannot be produced by the body and must be
present in the diet.
● Non-essential amino acids can be produced by the body and are
therefore not required as part of the diet.
● Conditionally non-essential amino acids can be produced by the body,
but at rates lower than certain conditional requirements (e.g. during
pregnancy or infancy) – they are essential at certain times only.
● A shortage of one or more essential amino acids in the diet will prevent
the production of specific proteins. This is known as protein deficiency
malnutrition and the health effects will vary depending on the amino
acid shortage.

Outline the cause and treatment of phenylketonuria (PKU)
● Phenylketonuria (PKU) is a
genetic condition that results
in the impaired metabolism of
the amino acid phenylalanine.
● It is a recessive disease
caused by a mutation to the
gene encoding the enzyme
phenylalanine hydroxylase.
● Normally excess
phenylalanine within the body
into tyrosine.
● In people with PKU, the excess
phenylalanine is instead converted into phenylpyruvate (also known as
phenylketone).
○ This results in a toxic build up of phenylketone in the blood and
urine (hence phenylketonuria).

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 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 studywithkiki. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £10.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

71250 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 15 years now

Start selling

Seller

Summary ·