Digestion Flashcards
Where does everything you eat go?
into your gut, or alimentary canal
What happens inside your gut?
big food molecules are broken down to make smaller molecules your body can use such as glucose. These molecules pass into your blood, which carries them to every cell.
What does mechanical digestion do?
it makes large food molecules easier to break down later.
What does saliva contain?
an enzyme that breaks down large molecules into smaller ones (chemical digestion)
What is the alimentary canal?
A long tube that winds its way from your mouth to your rectum.
What is mechanical digestion?
When solid lumps of food are broken down into smaller pieces through physical movement such as your teeth. This also happens in your gut (process of peristalsis).
What is a catalyst?
Chemicals that speed up chemical reactions without being used or changed. Biological catalysts are made up of living things.
What does emulsifies (fat) mean?
Breaks (fat) into smaller droplets.
What does denatured mean?
When an enzyme’s unique active site is disrupted and the substrate can no longer bind with the enzyme.
What does active site mean?
The unique shape of an enzyme where molecules are broken down.
How does saliva make food easier to swallow?
it is very slippery
What is chemical digestion?
the breaking down of large, insoluble molecules into small, soluble molecules by enzymes & using water, acids or alkalis.
What is an enzyme?
Protein that speeds up chemical reactions without being used up
What does your stomach blend each meal with?
acid and enzyme
What is the acid in your stomach?
hydrochloric acid
What does the hydrochloric acid in your stomach do?
it destroys microbes in your stomach while the enzyme (protease) begins the digestion of protein
What happens when your food is a smooth paste?
your stomach squeezes it out into your small intestine bit by bit
What is the longest part of your gut?
small intestine
Where are most large food molecules broken down?
small intestine
What do the walls of the small intestine do?
they squeeze food along and mix it with more enzymes that come from the pancreas
Where do small molecules pass through in the small intestine?
they are passed through the small intestine walls into your bloodstream, where you can use them
What is left when the food reaches the large intestine?
fibre
What is the large intestine full of?
bacteria that feed on the fibre and produce important vitamins that we can absorb
What do the large intestine walls do?
they absorb water from the bloodstream and use it to turn the mixture of fibre and bacteria into a solid waste called faeces (poop). It’s stored in your rectum until you are ready to excrete in the toilet 💩.
What would happen without enzymes?
most chemical reactions in your body would be too slow to keep you alive
What is the enzyme in saliva called?
amylase- it’s a type of carbohydrase because it breaks down starch
How does chewing food help enzymes?
it gives enzymes a larger surface area to work on, but fat molecules stick together in large globules
What happens as food enters the small intestine?
it mixes with bile from the gallbladder. Bile emulsifies fat
How does emulsifying fat help enzymes?
Emulsifying fat makes it easier for enzymes to work on since it has a larger surface area
How can enzymes be denatured?
by extreme temperatures and extreme pH values away from the optimum
What does optimum pH mean?
the pH at which enzymes work best
What is the order your food travels up the alimentary canal?
- mouth
- esophagus/gullet
- stomach
- small intestine
- large intestine
6.rectum/anus
What are the five stages of digestion?
- Ingestion- taking food into your body .
- Digestion- breaking food down into smaller soluble molecules.
- Absorption- taking in small, soluble molecules into the bloodstream.
- Assimilation – using the nutrients to build new cells for growth and repair.
- Egestion – the removal of waste products.
Where does the enzyme go in an equation?
on top of the arrow
What are the types of enzymes
amylase- from large insoluble starch to small soluble glucose (carbohydrates)
protease- from large insoluble proteins to small soluble amino acids (proteins)
lipase- from large insoluble fats to small soluble fatty acids and glycerol (fat)
What is villi?
Villi in small intestine with wall 1 cell thick and microvilli to increase surface area to absorb small soluble molecules into blood (glucose and amino acids) and lacteal (glycerol and fatty acids).
What is the pH in the mouth?
pH 7 (neutral)
What is the pH in the stomach?
pH 3 (acidic)
What is the pH in the small intestine?
pH 11 (alkaline)
What were enzymes used for before people knew what they were?
Enzymes were used for thousands of years in turning milk into cheese
How can enzymes turn milk to cheese?
by adding plant juices or animal stomach juices to the milk. (the juices have protease in them, and pure protease made by bacteria allowed much more cheese to be made.)
Where did we used to get starch from? And where do we get it from now?
We used to get starch from fruit, honey, sugar cane or sugar beet but nowadays, most sugar in processed foods comes from corn starch because it’s much cheaper.
What happens to these foods after the effect of lipase?
Bread
Dairy foods
Drinks
Sauces
Meat / fish
Health foods
Lasts longer / tastes better.
Improves taste.
Improved aroma (smell).
Smoother texture.
Fat removal.
Adds essential fatty acids.
Does the temperature have an impact on enzymes?
As temperature increases from 0◦C to 40 ◦C rate increases. Our body temperature is 37◦C so it is the ideal temperature or optimum temperature where it works best.
What happens if the temperature is too hot, too cold, oroptimum for enzymes?
Too cold – enzymes are slow
Optimum -enzymes work best
Too hot – enzymes denature and stop working.
What happens if an enzyme isn’t at its optimum pH
Enzymes’ active sites can change shape if the pH changes and so the substrate won’t fit and no reaction. The enzyme is denatured and stops working. Each enzyme has an optimum pH where it works best and a range in which they work
What is another word for your gut?
alimentary canal
what travels in a long thin tube from your mouth to your rectum?
Your gut
What are two examples of mechanical digestion?
mouth and teeth
What is an example of chemical digestion?
the enzyme that breaks down food in the saliva
What word means muscle contractions?
peristalsis
meaning of ingestion?
taking food into body
Meaning of Digestion?
breaking down food into small soluble molecules
meaning of absorption?
using the nutrients to build new cells for growth and tissue repair
Meaning of assimilation?
using the nutrients to build new cells for growth and tissue repair
meaning of egestion?
the removal of waste products
What does the large intestine absorb?
water
Which two foods have already started to be broken down before they enter the small intestine?
carbohydrates and proteins
What are the tiny structures in the small intestine called?
vili ( vilus )
Where is starch digested?
mouth and small intestine
Where is protein digested?
stomach and small intestine
Where is fat digested?
small intestine
