Topic 7- Macronutritents Flashcards
What are 4 chemical groupings are carbohydrates divided up into?
- Monosaccarides
- Disaccarides
- Oligosaccarides
- Polysaccarides
What are monosaccharides and disaccharides general referred to as?
- Sugars
What are oligosaccharides and polysaccharides?
They are composed of longer chains of monosaccharide units bound together by glycosidic bonds. The distinction between the two is based upon the number of monosaccharide units.
Distinction between oligo and polysaccharides?
Oligos typically contain between three and two monosaccharides (e.g. inulin), and polysaccharides contain greater than ten (often hundreds or thousands)
What do polysaccharides represent and what is their function?
They represent an important class of biological polymers and their function in living organisms is usually for structure or storage.
Eg. Starch- a polymer of glucose, is used as a storage polysaccharide in plants, being found in the form of both amylose and the branched amylopectin
Eg. Glycogen- another glucose polymer thats properties allow it to be metabolised more quickly which suits the lives of moving animals
Eg. Cellulose and chitin- these are examples of structural polysaccharides. Cellulose is used in call walls.
Roles that carbohydrates play in living cells?
- Polysaccarides serve for the storage of energy (starch and glycogen) and as structural components (cellulose)
- The 5 carbon monosaccharide robes in asn important component od coenzymes (e.g.. ATP, FAD, NAD) and the backbone of the genetic molecule known as RNA. The retiled deoxyribose in a component of DNA.
- Saccharides and their derivatives play a key roles in the immune system, fertilisation, blood clotting and development etc.
Are carbohydrates an essential nutrient in humans?
No
Can humans metabolise all types of carbohydrates?
No
What is the recommended percentage amount of daily energy intake that should come from carbs?
45-65%
What are complex carbs?
- They are straight or branched chained of monosaccharides
- The polymers formed and polysaccharides
- There are three main types -> glycogen, starch and fibre
What are the three main types of complex carbs?
- Starch
- Glycogen
- Fibre
What is glycogen?
- It a stored form for short term energy in animals (mainly liver)
- It is a branched glucose chain that can be readily hydrolysed
- Not found in plants and is not a significant food source
What is starch?
- Is a plant form of glucose storages
- Important food source for humans
- Found mainly in seed and underground plant roots\
- Two forms: amylose and amylopectin
What are the two formed of starch and which one is the most rapid to digest ?
- Amylose
- Amylopectin -> is the most rapid to digest
What is fibre?
- Is usually called non-starch polysaccharide (NSP)
- Consists of many compounds with different properties
- Main types include: cellulose, hemicellulose, pectine, gums and mucilages
- Most fibre cannot be digested in th human GI tract
- NSPs have varying bond types and monosaccharide units
- Cellulose in the predominant form of fibre in our diet, and consists of straight chains of glucose
- Cellulose in the building material for plans cell walls.
What are the main types of fibre?
Cellulose, hemicellulose, pectin, gums and mucilages
Where is hemicellulose (a type of fibre) found?
- Cereal fibers
Where are pectins many found (a type of fibre)?
- Fruits, vegetables and form gels in water
What are gums and mucilages composed of?
Wide variety of monosacchardies
What are the water soluble and insoluble fibres?
Water soluble:
- Gums
- Pectins
- Mucilages
- Some hemicellulose
Insolubles:
- Cellulose
- Lignin
- Some hemicellulose
Where are soluble fibres found (give examples)?
Found in plan foods including:
- Legumes
- Oats, chia, barley
- Some fruits and juices
- Certain vegetables such as broccoli, carrots and artichokes
- Root tubers and vegetables like potato and onions
- Psyllium seed husk ( a mucilage soluble fiber)
Where and insoluble fibres found?
- Whole grain foods
- Wheat and corn
- nuts and seeds
- Potato skins
- flax and hemp seed
- vegetables such as beans, cauliflowers, zucchini, celery
- Some fruits including avocado and bananas
- The skins in some fruits including kiwi and tomatoes
Fibre compounds with partial or lower fermentability include?
- cellulose and hemicellulose (polysaccharide)
- lignans, a group pf phytoestrogens
- plant waxes
- resistant starch
Fibre compounds with high fermentability include:
- beta-glucans (poly)
- pectins (hetropoly)
- natural gums (poly)
- Inulins (poly)
- Oligosaccharides
- Resistant dextrins