• Which enzyme in the Mouth act of starch?
• Which enzyme in the Mouth act on fat?
• What moistens food for swallowing?
• Which organ transports food to stomach?
• How long is food in the mouth?

• Salivary amylase acts on starch.
• Lingual lipase acts on fat.
• Saliva moistens food.
• Esophagus transports food to stomach.
• Transit time=1 minute.

• What 3 types of tissues make up the stomach?
• What connects the stomach to the duodenum?
• Why does it need to produce Intrinsic factor?
• How long in the food in the stomach?

• Longitudinal smooth muscle, circular smooth muscle, diagonal (oblique) smooth muscle,
• pyloric sphincter connects to duodenum
• to be able to absorb vitaminB12
• Transit time= 1-2hr
   

• Name the 3 sections of the small intestine
• What is the fuction of biocarbonate enzyme?
• What do pancreatic and intestinal enzymes breakdown?
• How long is food present in SI?
• What stuctures increase SA of SI for absorption.
• Most nutrients absorbed here but where do they go?

• Duodenum, jejunum, ileum
• Biocarbonate- neutalizes stomach acid.
• Break down carbohydrates, fats and proteins.
• Transit time= 7-8hr
• Folds, villi and microvilli
• Fat soluble> lymph and other nutrients> blood.

There are 3 types of absorptive processes-

• Explain passive diffusion
• Explain facilited diffusion
• Explain Active transport

• No energy needed-Water, water soluble substances (e.g urea, glycerol) and small lipids move with a concentration gradient down a transmembrane protein channel.
• No energy- carrier mediacted via special membrane proteins that change shape and allow the entry/exit of some nutrients (e.g. fructose)
• Requires energy- moves against conc gradient. inc minerals, ions, amino acids, glucose.

Carbohydrates

• Basic unit called a             which join together to make disaccharides, oligosaccharides/polysaccharides
• What are the 3 fuctions?
• Monosaccarides derive from aldehyde or ketones what is the difference?
• What r stereoisomers & when does it become an Enantomers and diasteriosomer?
• How do you know the difference between a D and L isomer? (CORN)

• Monosaccaride (1), dis (2), oligo(3-9), poly(many)
• energy source, structure, part of recognition molecules
• Aldehyde- Carbon connected to only one H or CH2 group. Ketone- Carbon connected to 2 CH2 groups.
• Stereoisomer-Isomers that have the same molecular formula and sequence but only differ in 3D structure.Enantomers-mirror image of each other e.g D and L-tartaric acid. Diasterisomers-dont reflect each other e.g D-tartaric acid and mesotartaric acid.
• CO>R>NH2 is a L form, D is when H is first.

Carbohydrate(2)

• The hydroxyl and either the keto/alde group can react to form a           and is now known as a anomer.
• A sugar with a 6 membered ring is a        
• A sugar with a 5 membered ring is a         
• An anomer can be      or      depending wether the glycosidic bond is above or below the ring

• Cyclic hemiacetals (ring structure) 
• pyranose e.g. glucose
• furanose e.g. fructose
• Alpha and beta.

Carb storage (starch)

• starch is the major storage in      
• What are the 2 types of glucose chains it contains and explain the structure
• Provides       % of dietry calories in humans

• plants
• Amylose- linear glucose with a1>4 gly bonds, forms a coil, amylopectin- contains a1>4 gly bonds and a1>6 bonds every 24-30 glucose molecules that form branches
• 80%

Carb storage (glycogen)

• Major storage carb in           
• Contains a1>6 bonds every       glucose molecules, therefore more       than starch
• Is it quicker to breakdown than starch, why?

• animals
• 4-8 molecules, therefore more branched than starch
•  less compact, more branches

Carb digestion

• Slivary amylase (a1-4 endoglycosidase) breaks the carbs into which 4 structures?
• In the small intestine,      enzymes (alpha-amylase) break amylose into what 2 products? and amylopectin into which 3 products?
• The oligosaccharide alpha-limit dextrin gets broken down in the SI but 5 other enzymes what could these be?
•              are absorbed in the SI by a          transporter

• alpa-Limit sextrins, maltotriose, maltose and isomaltose
• Amylose> maltotroise and maltose, Amylopectin> alpha-limit dectrins, maltotriose and maltose.
• Sucrase, alpha dectrinase, maltase, lactase and peptidase
• Monosaccarides by a hexose transporter

Cellulose is a main component of plant cell walls

• What type of bonds does it contain
• why cant vertebrates hydrolyse cellulose?
• What do ruminants have to be able to hydrolyse cellulose?

• Beta 1-4 gly bonds
• Do not possess an enzyme capable, need help from microorganisms
• digestive organs contain symbiotic bacteria that secrete cellulase

• Explain the structure of the following monosaccharides, where are they found?glucose, fructose, galactose
• Do the same for the following disaccharides- sucrose, lactose, maltose

• Glucose- 6C- fruits,veg etc, 'blood sugar' used for energy. Fructose- 5C 'fruit sugar'. Galactose- 6C found as part of lactose in milk.
• Sucrose- glucose + fructose, 'table sugar' made from sugar cane. Lactose- Glucose + glactose, from milk/diary. Maltose- glucose + glucose, found in germinating cereal grains and product of starch breakdown.

Diet Carbs

• What percentage of kilocalories should be consumed as carbs
• Daily value for 2,000 calories in grams is..
• How many grams of fibre?

• 55-60%
• 300g
• 25g per day

Carbohydrate malabsorption

• What is hypolactasia
• Latase enzyme production declines with      
• 2 main symptoms are...

• Lactose intolerance
• age
• gas, water retention