Unit 1: Section 2 - The Digestive System Flashcards
Polymers are long chains of?
Monomers
Digestion is the process in which……………?
Large molecules are hydrolysed by enzymes to produce smaller molecules that can be absorbed and assimilated
Are protein and most carbohydrates polymers or monomers?
Polymers
In carbohydrates the monomers are called?
Monosaccharides
In proteins the monomers are called?
Amino acids
What elements to monosaccharides contain?
Carbon, hydrogen and oxygen
What elements do amino acids contain?
Carbon, hydrogen, oxygen and nitrogen
Which element is present only in monomers in protein?
Nitrogen
What’s the difference between absorption and assimilation?
Absorption is when molecules move from the digestive system into the blood where as assimilation is where absorbed molecules are incorporated into body tissues
What’s is assimilation?
Assimilation is where absorbed molecules are incorporated into body tissues
How does physical digestion happen in the mouth and stomach?
By the teeth in the mouth, and by the churning movement of the stomach muscles in the stomach
Why does physical digestion make digestion easier?
It breaks down food into smaller pieces giving a larger surface area for chemical digestion to take place on
What happens during chemical digestion?
Polymers are hydrolysed into smaller more soluble molecules which can be absorbed
How is the digestive process started in the mouth?
Teeth begin to break down the food (physical digestion) and the tongue is used to push food down the oesophagus
Why is saliva secreted?
Makes food easier to swallow and it contains enzymes which start chemical digestion
How is the digestive process continued in the oesophagus?
It takes food from the mouth to the stomach using peristalsis
What is peristalsis?
Wave like movements caused by contraction and relaxation of muscles, pushing food down the digestive tract
Why is mucus secreted in the oesophagus?
To lubricate the foods passage downwards
How is the digestive process continued in the stomach?
The stomach walls produce gastric juice to break down the food in the stomach (chemical digestion). Any the peristalsis of the stomach turn food into an acidic fluid called chyme
What do gastric juices contain?
Hydrochloric acid, pepsin and mucus
What are the two main parts of the small intestine?
Duodenum and ileum
The duodenum and ileum are parts of the?
Small intestine
What happens in the duodenum?
Bile and pancreatic juice neutralise the acidity of the chyme and break it down into smaller molecules
What happens in the ileum?
Small soluble molecules are absorbed through villi in the lining of the walls