Biology Unit 2: Biological Molecules and Digestion Flashcards
What is Chemical Digestion?
Chemical digestion involves the various chemicals and enzymes that our body
produces, it breaks food down into molecules small enough to absorb
What is Physical Digestion?
Physical digestion involves some kind of movement/crushing/mixing, it mostly happens in the mouth and stomach.
What are the Parts of Digestion?
- Mouth,
- Oesophagus/gullet,
- Stomach,
- Small Intestine,
- Large Intestine,
- Liver,
- Pancreas
Digestion: Mouth
The start of the alimentary canal.
The teeth break up food into smaller pieces (mechanical digestion) so there is more surface area for the various enzymes to digest food into small enough pieces to absorb.
Starch, a complex carbohydrate, starts breaking down here because of an enzyme in the saliva.
Digestion: Oesophagus/gullet
The tube that connects the mouth and the stomach.
Food moves through this tube after it is swallowed and is pushed down by circular muscles.
This process is called peristalsis and is the reason you can swallow even if you are upside down.
Digestion: Stomach
A muscular bag that mixes and breaks down chewed up food (more mechanical digestion).
It contains acid that kills most bacteria and other microbes and an enzyme that breaks down protein into amino acids (chemical digestion).
Digestion: Small Intestine
More enzymes are released at the start of the small intestine and food keeps getting broken down into molecules that can be absorbed (more chemical digestion).
Most of the absorption of nutrient molecules occurs here. It is the longest part of the alimentary canal
Digestion: Large Intestine
Most of the nutrients have been absorbed by the time digested food gets here.
Water is reabsorbed so it can be used in other parts of the body.
The undigested parts (faeces) are pushed through by muscular contractions (peristalsis again) and are eventually removed via the anus.
Digestion: Liver
Is a very large and important organ.
- It helps break down toxins,
- helps control the amount of sugar in our blood,
- and makes bile which helps our body digest and absorb lipids.
Digestion: Pancreas
What is Digestion?
Breaking down of food to make nutrient molecules available to the body
What is an Enzyme?
A protein that acts as a biological catalyst and speeds up chemical reactions
What is a Carbohydrate?
A nutrient molecule that is the main source of energy
What is a Protein?
A Protein is a nutrient molecule that is used for growth and repair
What is a Lipid?
A Lipid is a nutrient molecule that is used for energy, extra energy is also stored in this form in the body
What is Fibre?
Fibre is a material that is not digested and keeps the bowels functioning correctly
What elements do Carbohydrates contain?
- Carbon (C),
- Hydrogen (H)
- Oxygen (O)
What types of Carbohydrates are there?
They can be
- simple like glucose and other sugars, or
- complex like starch.
How are Complex Carbohydrates digested?
When complex carbohydrates are digested they are broken down into sugars that our bodies can use for respiration.
What do our Bodies use energy For?
Our Body uses Energy for Life Processes like growth, movement, and keeping us warm
What are Some foods high in Carbohydrates?
Some Foods high in Carbohydrates: Bread , Pasta , Rice, Corn , Potatoes, Fruit
What are Proteins?
Proteins are the main source of new building material
How are Proteins Digested?
Proteins are Broken Down and made into New Proteins in our bodies.
What are Proteins Made up of?
Proteins are made up from molecules called Amino Acids, these amino acids are used to make all of the different proteins in our bodies, like muscle protein.
