B7 (Human nutrition) Flashcards
What does a balanced diet contain?
All the nutrients needed by the body, in the correct amounts to maintain health
What are carbohydrates
compounds found in living things composed of carbon, hydrogen and oxygen
What are fats?
A compound that consists of glycerol and fatty acids
What are proteins?
Made of amino acids- used to synthesise muscle, skin, bone, and enzymes. Sources
What are protein’s functions
-structural support
-biochemical catalyst
-hormone
-building block
What are vitamins
a group of micronutrients essential for healthy metabolic processes - found in fruits and vegetables
e.g C,B (water soluble) A, D, E, K (fat soluble)
What are coenzymes
small molecules that attach to enzymes and help them catalyse reactions
vitamins are used as coenzymes
examples of minerals
Calcium, phosphorus- strong bones and teeth
iron- hemoglobin, myoglobin (proteins in muscle cells) production
Zinc- proper immune function
what is fibre
type of carbohydrate that the body cannot digest
e.g cellulose - plant based carb
What is the role of water in the body
-metabolism improved
-plasma blood
-waste removal
-thermoregulation
-joint lubrication
(needed in almost every process)
Sources of carbs
fruit, vegetables, pasta, bread, potatoes
function of carbs
provides energy
sources of fats
avocado, nuts, olive oil, oily fish
function of fats
provides energy
sources of proteins
meat, fish, eggs, beans, pulses, nuts
main function of proteins
growth and repair
sources of vitamin C
oranges, red pepers, kale, broccoli
function of Vitamin C
maintains healthy blood vessels, skin, cartilage and bones
helps heal wounds
Sources of vitamin D
salmon, cheese, eggs
Function of vitamin D
regulate the amount of calcium and phosphate in the body
keeps teeth, bones and muscles healthy
sources of calcium (mineral)
milk, sardines, broccoli, kale, okra, spinach
sources of iron (mineral)
red meat, beans, nuts
Function of calcium
strong bones and teeth
muscle contraction and clotting of wounds
Function of iron
production of haemoglobin for red blood cells
how much of body mass is water
about 60%
sources of fibre
cereals, vegetables, fruit, brown rice, nuts, potatoes
Function of fibre
helps digestion and moving food and faeces along the gut
associated with lower risks of heart disease, type 2 diabetes and bowel cancer
sources of water
water and other drinks
what is a deficiency disease?
an illness caused by the lack of an essential nutrient in the diet such as vitamin, minerals or even protein
What happens due to a vitamin D deficiency?
rickets
Symptoms of rickets
bone pain
weakness in the muscles
bone loss with increased risk of fractures and skeletal deformities
what happens due to a vitamin C deficiency?
scurvy
symptoms of scurvy
severe leg pain or join pain
tiredness
weakness
blue or red spots on the skin which bruise easily
swollen or bleeding gums
What is digestion?
The breakdown of large, insoluble food molecules into smaller, water soluble molecules that can be transported across membranes and used for metabolism
What are the two types of digestion?
Physical/mechanical
Chemical
What is physical digestion?
involves breaking down food into smaller pieces without any chemical changes
happens in: mouth, stomach (movement of the stomach walls)
What is chemical digestion?
involves breaking down large insoluble molecules in food into small soluble molecules, with the help of enzymes
This happens in: the mouth, the stomach, the small intestine
define ingestion
the taking in of substances into the body through the mouth
What two functions does the mouth have?
digestion- amylase breaks down carbs
ingestion- food is taken in through the mouth
both ___________ and ___________digestion happen in the mouth
chemical
mechanical
Define absorption
the movement of digested food molecules through the wall of the (mostly small) intestine into the blood.
Define assimilation
the movement of digested food molecules into the cells of the body where they are needed.
Define egestion
the passing out of food that hasn’t been digested as faeces through the anus
How is egestion and excretion different?
excretion is the removal of waste products of metabolic processes.
Where in the body does ingestion happen?
mouth- it is then swallowed and passed down the oesophagus
where does digestion happen?
mechanic: in the mouth, stomach (walls moving to break food into small pieces)
chemical: mouth, stomach, small intestine
where does absorption happen?
small intestine
Where does assimilation happen?
happens throughout the body
e.g amino acids are converted into proteins in the liver
Where does egestion happen?
faeces are stroed in the rectum.
passed through the anus
what is the alimentary canal (gut)?
tube in which food passes through the body- food enters the mouth then leaves at the anus
What journey does food take
mouth
oesophagus
stomach
small intestine
large intestine
anus
(alimentary canal)
what parts does the small intestine consist of
duodenum
ileum
What parts does large intestine consist of?
colon
rectum
what are salivary glands
glands in the mouth which secrete saliva containing amylase (starch)
what is the liver
organ that produces bile which emulsifies fats and neutralises the acidic chyme from the stomach
what is the gall bladder
sac like structure which stores bile before release into the duodenum
What is the pancreas
A gland located behind the stomach that secretes digestive enzymes (protease, lipase, carbohydrase) and the hormones insulin and glucagon
function of stomach
food is mixed with enzymes and acid here- churned up by strong muscles (physical digestion)
What is the duodenum?
section of the small intestine connected to the liver, gall bladder and pancreas which supplies it with bile and lots of enzymes
function of the small intestine
where food is absorbed into the bloodstream and taken to the parts of the body
function of the large intestine
any part of the food which can’t be digested are stored here as faeces before being egested via the anus
water is reabsorbed from the digesting food
Is pancreatic juice alkaline or acidic
alkaline - contains a high concentration of hydrogen carbonate ions
neutralises acid in the food leaving the stomach
What role does HCL in the stomach play?
in denaturing enzymes in harmful microorganisms, thereby killing bacteria in food
provides optimum PH for protease activity
protease if found in the _______ and breaks down _______, producing _________
stomach
proteins
amino acids
Lipase is found in the _________(duodenum) and breaks down lipids, producing _______ and _____ acids
small intestine
glycerol
fatty
amylase is found in the _________ and __________ and breaks down _______, producing simpler sugars e.g _______, _______, ________
mouth+small intestine (duodenum)
starch
glucose, lactose, sucrose
What is the function of bile?
Helps to neutralise the acidic mixture of food and gastric juices entering the duodenum from the stomach
emulsifies fats
enables a suitable PH for enzyme action in the small intestine
What does the emulsion of fats mean?
increases surface area for lipase to act on by breaking fats into small droplets (mechanical digestion)
How is the small intestine adapted for efficient absorption?
Large surface area: Millions of villi and microvilli increase absorption and membrane is maximised and folded, increasing s.a
Short diffusion distance: One-cell-thick walls and proximity to capillaries speed up diffusion.
Good blood supply: Maintains concentration gradients for efficient diffusion.
Active transport: Mitochondria provide energy for absorbing nutrients against the gradient.
Lacteal branch: Transports lipids from the intestine into the lymphatic system.
What are lacteals, and what do they do?
Lacteals are lymphatic vessels in the small intestine that absorb digested lipids.
What are villi (villus sing.)
finger-like protrusions on the wall of the small intestine that increase its surface area for nutrient absorption.
