module 3 (food and digestion) Flashcards
what are fats needed for?
they contain lots of energy and can be stored in the body to keep heat in
what is protein needed for?
for growth and to repair damaged tissues in the body
what are minerals needed for?
needed in small amounts to make important structures in the body (eg. blood cells)
what are carbohydrates needed for?
broken down in cells during respiration to release energy so we can move and keep warm
what are vitamins needed for?
needed in tiny amounts to keep us healthy
what is fibre needed for?
needed to keep the gut in good condition and to help prevent constipation and bowel cancer
define a balanced diet
eating a variety of different food groups in the correct proportions
define malnutrition
a lack of proper nutrition often caused by not having enough to eat or not eating the right balance of nutrients
define deficiency disease
a disease caused by the lack of an element in the diet, usually a particular vitamin or mineral
what is the calculation for the daily energy requirements
basic metabolic rate + physical activity level
how do you test for reducing sugars?
benedict’s solution and heat (if sugar is present the colour changes from blue to orange)
how do you test for starch?
iodine solution (if starch is present the iodine solution turns blue/black)
how do you test for protein?
biuret chemical (if protein is present the colour changes from pale blue to violet)
how do you test for lipids (fats)?
ethanol (if fat is present the solution turns cloudy and an emulsion will form)
what does the mouth do?
teeth chew (mastication) food into smaller pieces and saliva contains the enzyme amylase that breaks down carbohydrates into sugars
what does the oesophagus do?
a muscular tube that delivers food from your mouth to your stomach, the muscle contracts (peristalsis) to push food
what does the stomach do?
a muscular bag which churns up food in hydrochloric acid and dissolves food into a thick liquid, enzymes are also released to break down proteins
what does the small intestine do?
enzymes digest food from insoluble to soluble molecules that can enter the bloodstream, villi absorb broken down nutrients into the bloodstream, villi have micro villi
what does the large intestine do?
insoluble food is broken down by bacteria into vitamins and minerals that can be absorbed, excess water is also absorbed and feces is made
what does the rectum do?
stores waste until it exits the body
what does the anus do?
expels waste from the body
define digestion
the process of breaking large insoluble molecules of food into smaller soluble molecules of food
define enzymes
chemicals which break the larger molecules down into smaller molecules, they usually end in ase
define a parasite
an organism that lives in or on another organism (the host)
