Ch28: Human Nutrition Flashcards
(48 cards)
What is an autotroph?
Makes their own food
What is a heterotroph?
Take in food from the environment
What is a parasite?
A heterotroph that feeds on live sources
What is a saprophyte?
A heterotroph that feeds on dead matter
What is a herbivore?
Animals that feed mainly on plants
What is a carnivore?
Animals that feed mainly on other animals
What is an omnivore?
Animals that feed on both plants and animals
Other names for digestive system?
Alimentary canal or gut
Why do organisms need to digest food?
-Energy
-Growth and repair
-Metabolic reactions
Why do we need the digestive system?
So that digestive enzymes are not needed in every cell in the body, like tapeworms
Name and explain the four processes involved in the digestive system
-Ingestion: taking in food
-Digestion: breakdown of food
-Absorption: food passes into blood
-Egestion: removal of undigested food
Name the types of teeth and their functions
-Incisors: for cutting and slicing
-Canines: for gripping and tearing
-Premolars: for crushing and grinding
-Molars: for crushing and grinding
How many teeth does an adult human have and write the Dental formula
32 teeth
2(I 22, C 11, P 22, M 33)
Name and explain the two types of digestion in the mouth
-Chemical digestion: action of the enzyme, amylase, breaking down food
-Mechanical digestion: chewing and grinding action of teeth breaks down food
What does saliva contain?
Water, salts, lysozyme (destroys bacteria) and amylase
Amylase:
1. Production site
2. Activity site
3. Substrate
4. Product
5. Optimum pH
- Salivary glands/ Pancreas
- Mouth/Duodenum
- Starch
- Maltose
- pH7
What is the function of the epiglottis?
A flap of cartilage that closes over the trachea to ensure food passes into the oesophagus
Function of oesophagus?
Carries food from the mouth to the stomach by peristalsis
What is peristalsis?
A wave of muscular actions in the wall of the alimentary canal that moves the contents along
-form of mechanical digestion
What is the role of fibre in the digestive system?
Fibre stimulates peristalsis by causing waste to absorb water and expand
Function of the stomach?
-Muscular bag that holds and digests food
-Churns food with gastric juice to form chyme
Name and explain the 2 types of digestion in the stomach
-Mechanical digestion: Churns food
-Chemical digestion: action of gastric juice
What is the role of mucus?
Coats the stomach to prevent self-digestion
Role of hydrochloric acid in the stomach?
-Gives a pH of 1-2
-Kills bacteria
-Loosens food
-Activates pepsinogen