Digestion/ Metabolism Flashcards
What is metabolism
Chemical processes that occur in the body’s cells to provide the body with energy
What is catabolic metabolism
Breaking down of compounds, releasing energy ( digestion)
What is anabolic metabolism
Building up ( or synthesis) of compounds, consumes energy ( growth )
Describe carbohydrate catabolism
Complex starches are broken down into monosaccharides via a series of digestive enzymes e.g amylase
Once monosaccharides is in the cytoplasm it is broken down further through glycolysis ( glucose being broken down into pyruvate and ATP)
Describe protein catabolism
Proteins are broken down into amino acids via digestive enzymes e.g. pepsin
Essential amino acids - can’t be synthesised by the body so must be eaten in diet
Non-essential amino acids can be synthesised by the body so don’t need to be included in diet
Nitrogen balance- body needs specific amount of amino acids ( negative - body doesn’t have enough and positive- body has more than required so will break down)
What are amino acids used for
Growth and repair of tissues and cells
Making new proteins e.g. enzymes, antibodies
Providing energy if there is no carbohydrate or fat available
What is deamination
Removal of an amino group
This creates the by-products CO2 and ammonia which is converted into urea by the liver which is excreted by the kidneys into urine
Describe different types of fats
Triglycerides- 3 fatty acids + glycerol, commonly known as fat
Cholesterol- different structure to triglycerides, needed to make steroid hormones in the body
‘good’ cholesterol known as HDL protects cardiovascular health
‘bad’ cholesterol known as LDL associated with poor cardiovascular health, clogs arteries
Describe fat catabolism
Triglycerides are broken down into fatty acids and glycerol via the process of hydrolysis
The glycerol that has been released is turned into energy via glycolysis
Describe the role of the pancreas
Endocrine part releases hormones:
Insulin = reduces high blood sugar levels, produced by beta cells, released into bloodstream when blood glucose is high, helps glucose move along cell membrane
Glucagon = increases low blood sugar levels, produced by alpha cells, released into bloodstream when blood glucose levels are low, breaks down glycogen stored in liver into glucose
Exocrine part secretes something down a tube
What is gluconeogenesis
The process of creating glucose e.g. from glycerol, lactate, pyruvate
Turns non-carbohydrate substances to glucose to maintain blood glucose levels
What is glycogenesis
The process of turning glucose to glycogen
If there is excess glucose this process occurs to be stored by the liver for when needed
What is glycogenolysis
The process of breaking glycogen into glucose
Low glucose means this process can occur to allow more glucose
