SAC 2 - Unit 3 - Eating and digesting food Flashcards
(47 cards)
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
