SAC 2 - Unit 3 - Eating and digesting food Flashcards
Appetite definition
The desire for food even when the body is not hungry
Chemical digestion definition
Is the breakdown of food using chemicals such as enzymes and acids
Enzymatic hydrolysis definition
Is a chemical digestive process that breaks down food by breaking the bonds that hold together the molecular ‘building. blocks’ within the food
Hunger definition
The drive to satisfy the need for food
Mechanical digestion definition
The use of physical to break down food, such as chewing or squashing movement of the intestines
Satiety definition
A state or feeling of fullness after eating food
How does hunger differ from appetite?
Appetite is the desire for food even when the body is not hungry whereas hunger is the drive to satisfy the need for food
Satiety and 2 food with low and high satiety levels
Satiety is a state or feeling of fullness after eating food
Two foods with low satiety levels are
- Pastries
- Sweet biscuits
Two foods with high satiety levels are
- Meat
- Pasta
Whats the difference between mechanical and chemical digestion and two examples of each
Mechanical digestion is the use of physical force such s chewing or squashing movements of the stomach or intestines
- Action of teeth and tongue
- Churning action of the stomach
Chemical digestion is the breakdown of food using chemicals such as enzymes and acids
- Action of saliva in the mouth
- Release of gastric juices in the stomach
what is a villi
a structure in the inside of the small intestine which are used for absorption. In the centre of each villus is the lacteal which is surrounded bu tiny blood capillaries
what happens what the villi are damaged
nutrients cannot be absorbed properly. gluten irritates the villi causing them to shrink and flatten so they are less effective in absorbing the nutrients
where does the digestion process start
in the mouth
what does the pancreas do
it secretes both digestive juices and insulin
what does the liver do
the liver produces bile, which is secreted into the duodenum where it emulsifies fat
during digestion, what are proteins broken down into
amino acids
what is the purpose of amino acids
amino acids are the building blocks for protein synthesis for the creation of new tissue, cells and hair
macronutrients
nutrients that provide the body with energy. there nutrients are carbohydrates, proteins and fat
explain what it is meant my satiety
Satiety is the sense of fullness that comes after eating food and when there is no further desire for food
outline the differences between chemical digestion and mechanical digestion
Mechanical digestion is the use of force, such as chewing or the churning or squashing movements of the stomach or intestines, to break down food. Chemical digestion the breakdown of food suing enzymes and acids secreted by digestive glands
What is enzymatic hydrolysis
A chemical digestive process that breaks down food by breaking the bonds that hold the molecular ‘building blocks’ within the food together. Reactions occur when an enzyme incorporates a water molecule across the bond allowing it to break. Occurs in the small intestine
describe the changes that occur to the following sugars in the small intestine and the enzymes involved
Sucrose - the small intestine secretes sucrase to break down sucrose into glucose
Lactose - is broken down into galactose by lactase
Maltose - is broken down into glucose by maltase
Explain how the structure of the villi assists the process of absorption of nutrients
Villi are finger-like projections, which create a large surface area that allows the tiny units of each nutrient to pass through into either the bloodstream of the lymphatic system
Describe what happens when the villi are damaged and how this impacts on the absorption process
if the villi are damaged, nutrients cannot be absorbed properly. This occurs unpeople ho have coeliac disease. The gluten in the villi, causing them to shrink and flatten and be less effective in absorbing the nutrients
Explain how digested carbohydrates are utilised by the body for energy
Digested carbohydrates are converted to glucose and is transported to the body cells via the blood stream. Its movement and the amount released into the bloodstream is controlled by the release in insulin. Once in the cells it combines with oxygen to form energy
Monosaccharides
single units of sugar that are the base unit from which other carbohydrates are built
examples of monosaccharides
- glucose
- fructose
- galactose
Disaccharides
made up of two monosaccharides
examples of disaccharides
- sucrose
- lactose
- maltose
Polysaccharides
made up of three or more monosaccharids
Polysaccharides
made up of three or more monosaccharides
These are carbohydrates made form many sugar units and are known as starches.
These form during photosynthesis when a number of monosaccharides join together.
They are tasteless converted to glucose during digestion.
Found mainly in cereals and starch vegetables such as potatoes
why resistant starch is valuable in the digestive process
resistant starch resists digestion in the small intestine and is valuable for bowel health by promoting the growth of healthy bacteria
what are microflora? how are microflora important in the digestive system
The intestinal tract is a complex ecosystem and contains over 400 species and over 100 trillion individuals bacteria called microflora. They improve digestion and the absorption of short chain fatty acids and the assist with the synthesis of vitamin B and K . They are particularly important in aiding the digestion of lactose, reducing diarrhoea in lactose-intolerant people
how are fats absorbed
during absorption, fats are broken into fatty acids and glycerol. These fatty acids and glycerol are absorbed into the lacteal or inner section of the villi in the small intestine. In the lacteal, they recombine to form fats, which mix with lymphatic fluid. They then move around the body in the lymphatic system, and join the blood circulation as insoluble fat. They are converted to soluble fat in the liver
coeliac disease
disease of the small intestine
in a person who suffers form coeliac disease, the lining of the small intestine is damaged by gluten
coeliac substitute
rice flour
what foods to avoid with coeliac disease
bread pizza cereals cakes biscuits pies
lactose intolerant
milk and other dairy products
lactose substitute
lactose free milk
signs of a food allergy
anaphylactic reaction
symptoms of a food allergy
hives rashes asthma stomach pain diarrheoa
foods that cause allergies
fish shell fish dairy eggs nuts
how is hepatitas A spread
transferred from the faeces if an infected person contaminated food, drinks or food-handling equipment through poor personal hygiene. spread through water
hepatitas A symptoms
fever nausea abdominal pain dark urine jaundice
how can hepatitas A be avoided
Avoid water that could be contaminated with fecal matter. Avoid undercooked or raw shellfish.
Always wash your hands with soap and water after using the bathroom or changing a diaper and before preparing and eating food.
how is salmonella spread
when food that contains the live bacteria from contaminated food products, water or hands is eaten
salmonella symptoms
nausea headaches fever diarrhoea abdominal cramps
how can salmonella be avoided
Wash your hands before preparing food and after handling raw meats.
Cook meat and eggs thoroughly until they reach an internal temperature of 160 F (71 C) Do not eat foods containing raw eggs or milk, such as undercooked French toast.
how can salmonella be avoided
Wash your hands before preparing food and after handling raw meats.
Cook meat and eggs thoroughly
Do not eat foods containing raw eggs or milk, such as undercooked French toast.
how can salmonella be avoided
Wash your hands before preparing food and after handling raw meats.
Cook meat and eggs thoroughly
Do not eat foods containing raw eggs or milk
