The Digestve System Flashcards
What’s the formula for BMI?
Weight in kilograms divided by height squared in metres
What is a source of carbohydrates?
Bread, pasta, rice and potatoes
What is the role of carbohydrates?
Starch is an energy source of glucose, which is the main substrate for cellular respiration to produce a TP
What are sources of protein?
Red and white meat, fish and nuts
What is the role of proteins?
Proteins are broken down into amino acids which are used to make the globular and fibrous proteins of the body
What are sources of lipids?
Cheese, yoghurt, and chocolate
What are the roles of lipids?
Triglycerides are dense source of energy. Phospholipids are used to make cell membranes. Cholesteryl is used to make steroids.
What is a source of vitamin C, K, A, and B
Vitamin C can be found in citrus fruits
Vitamin K can be found a green leafy veg
Vitamins a and B can be found in dairy fish, liver, cereals and root veg
What is the role of vitamin vitamin C, vitamin K, Vitamin A, and vitamin B
Vitamin C is used for collagen synthesis (tissue growth and repair) and iron absorption and immune system
Vitamin K is used for normal blood clotting in response to vessel injury
Vitamins A and B are used to maintain teeth, bones, soft tissue, mucus membranes skin and brain function
What are sources of the minerals, iron, calcium, phosphate, sodium and potassium? 
Calcium can be found in dairy
Iron can be found in red meat and green leafy veg
Phosphate can be found in processed meat, Coca-Cola and baked goods
Sodium is found in salt
Potassium found in fruit
What are the roles of the mineral is iron, calcium, phosphate, sodium and potassium
iron is used for haemoglobin for oxygen transport
Calcium is used for exocytosis in the endocrine system and nervous system and muscle contractions and bone formation
Phosphate is used in ATP synthesis
Sodium is used for nervous system function and so is potassium 
What is the source of water?
Drink and food
What is the role of water?
Water is the main liquid of the bodies fluids: blood, cytoplasm, tissue fluid, and lymph fluid
What is a source of fibre?
Vegetables and salad
What is the role of fibre
Supports the digestive biscuit system functions, and helps prevent constipation 
Describe the role of the mouth in the digestive system
The mouth contains specialised teeth. These chew the food and break it into smaller pieces. This is mechanical digestion. The tongue mixes food with saliva to aid chemical digestion. The tongue also pushes a rolled up bolus of food to the back of the mouth, so you can swallow it 
Describe the role of the oesophagus in the digestive system
Do you suffer Gus or food pipe joins the mouth to the stomach. Food is squeezed along this tube into the stomach by smooth muscle contractions called peristalsis.
Describe the role of the stomach in the digestive system
The stomach is a bag of hydrochloric acid. The acid in the stomach and special chemicals called enzymes chemically break down the food even more. 
Describe the role of the small intestine in the digestive system
The small intestine is 6-7 m long. In the small intestine the food is chemically broken down further by incoming pancreatic juices and overlaying intestinal chemicals. The products of food are then absorbed into the blood so the body can use them.
Describe the role of the large intestine in the digestive system
The large intestine is about 1.5 m long. In the large intestine, the body absorbs a lot of water back from the digested food. The remaining dried out material forms, waste/faeces 💩
Describe the role of the rectum in the digestive system
At the end of the digestive system, the leftover material that the body can’t use (faeces) exits the body from the rectum through the anus. This process is known as defecation. 
What is the role of the liver in the digestive system
Delivers main function is the process, the nutrients absorbed from the small intestine. While bile from the liver secreted into the small intestine also plays an important role in digesting fats and some vitamins. 
What is the role of the gallbladder in the digestive system?
The gallbladder stores and concentrates bile from the liver, and then release is it in to the duodenum in the small intestine to help absorb and digest fats
What is the role of the pancreas in the digestive system?
The pancreas secretes digestive enzymes into the Duodenum and that breaks down protein fats and carbohydrates.
The pancreas also makes insulin passing it directly into the bloodstream 
Describe the enzymes in found in the mouth for digestion
Salivary glands secrete amylase into the mouth for starch digestion 
Describe the enzymes in the stomach for digestion
Amylase breaks down starches and carbohydrates into sugars. Protease breaks down proteins into amino acids. Lipase breaks down lipids, which are fats and oils into glycerol and fatty acids. 
Describe the enzymes in liver
Liver makes bile which contains bile salts to emulsify lipids in the small intestine
Describe the Enzymes in the pancreas
Pancreas secrete, amylase, peptidases (including trypsin) and lipase into the small intestine 
Describe the ileum
The ileum is a part of the small intestine which has folds called villi to increase surface area for digestion and absorption. Villi are lined by epithelial cells which have microvilli on the surface.
Microvilli have membrane-bound disaccharides, which digest maltose and glucose and dipeptides, which digest dipeptides into amino acids. The ileum is also the site where are the products of digestion are absorbed from the gut lumen into blood capillaries or lacteals. 
What is mechanical digestion?
The breakdown of large masses of food particles into smaller masses of food particles. Does not involve breakage of specific bio chemical bonds holding bio molecules together. Examples are:
Mastication and chewing with teeth and tongue.
Mixing and segmentation in the tract.
Bile salt emulsification of lipids.
Describe chemical digestion
Denaturing biochemical molecules (protein) in food, using acid baths (Stomach HCL). Hydrolysis of biochemical molecules in food using specific digestive enzymes to break particular bio chemical bonds. Specific enzymes have a unique active site which accommodate a complimentary substrate. Different types of enzymes each biochemical molecule. Work at different sites in the digestive tract are sure chemical digestion is efficient.
What happens to the large molecules during digestions?
Your food contains large, biological molecules for example, starch and proteins which are too large to cross cell membranes. During digestion, these large molecules are broken down into smaller molecules for example, glucose and amino acids which can move across cell membranes so can easily be absorbed from the food. Large molecules are broken down during catabolic reactions.
What are polysaccharide carbohydrates broken down into
Monosaccharides and disaccharides
Fats broken down into
Fatty acids and monoglycerides
Proteins are broken down into
Amino acids
Where does salivary amylase come from and what does it do?
Salivary amylase comes from the salivary glands in the mouth and matches with starch to turn into maltose the conditions required for this to happen are neutral
Where does pancreatic amylase come from and what does it do?
Pancreatic amylase comes from the pancreas in the small intestine (duodenum) and turns starch into maltose the conditions required for this are an alkaline ph
Where does the enzyme maltase come from and what does it do?
Maltese is attached to microvilli on the intestinal wall and turns maltose into glucose, and it needs alkaline condition for this to happen
Where does the enzyme pepsin come from and what does it do?
Pepsin is secreted in the stomach and turns protein into smaller polypeptide. It needs an acidic condition to do this.
Where does the enzyme trypsin come from and what does it do?
Tropes and is secreted in the pancreas into the small intestine, also known as the duodenum it turns small polypeptides into dipeptides and needs an alkaline condition for this to happen 
Where does dipeptides has come from and what do they do
Dipeptides are attached to the small intestine microvilli wall, also known as the ileum. It turns dipeptides into amino acids and needs an alkaline condition for this to happen. 
Where does the enzyme salivary lippies come from and what does it do?
Salivary, LaFace comes from the salivary glands in the mouth, and turns lipids or triglycerides into monoglycerides and fatty acids. It needs neutral or acidic conditions for this to happen. 
Where does the enzyme pancreatic lipase come from and what does it do?
Pancreatic lippies is secreted from the pancreas into the small intestine also known as the duodenum it turns lipids or triglycerides into monoglycerides and fatty acids. It needs alkaline conditions and bile salt, emulsification of large fat globs for this to occur.
What are the polymers involved with the bio molecule carbohydrates, proteins and lipids? 
The polymers in carbohydrates are polysaccharide starch, glycogen disaccharides, and maltose.
The polymers in proteins are proteins dipeptides and dipeptides.
The polymers in lipids are triglycerides. 
What enzyme or digestive chemicals are involved with the biomolecules carbohydrates, proteins and lipids
The enzyme for carbohydrates are amylase and disacchariase.
The enzyme for proteins are HCl, protease (or pepsin and trypsin), exopeptidase, endopeptidase, and dipeptidase.
The enzyme for lipids are lipase and bile salts.
What is the site where digestion occurs for the biomolecules carbohydrates, proteins and lipids
The site where digestion occurs for carbohydrates is in the mouth, small intestine lumen, and the small intestines surface.
The site where digestion occurs for proteins is the stomach, small intestine lumen, and the small intestines surface.
The sites were digestion occurs for lipids, is the small intestine lumen.
What are the monomers for the biomolecules carbohydrates, proteins and lipids? 
The monomers for carbohydrates are monosaccharides and glucose.
The monomers proteins are amino acids.
The monomers for lipids of fatty acids and monoglycerol.
What is amylase?
Amylase is a digestive enzyme made by the salivary glands and pancreas. It is secreted into the mouth and into the small intestine. The two places where it acts
What does amylase breakdown and how?
Amylase breaks down starch by hydrolysing, Glycosidic bond, to produce maltose a disaccharide
This disaccharide is still too big to be absorbed in the gut, so?
It has to be digested by second enzyme called maltaseto make glucose which is a monosaccharide small enough to be absorbed. So it takes quite a long time to break down starch to glucose.
Disaccharides are enzymes that are attached to what
The cell surface membranes of epithelial cells lining the ileum, which is the final part of the small intestine 
What is the benefit of attaching enzymes in this way?
They are not lost in faeces, unlike enzymes which are secreted into the gut
The surfaces of the cells are folded into what? which increases what?
The surface of the cells are folded into micro villi, which increases the surface area for enzyme attachment and absorption of the products of digestion
Disaccharidases catalyse is the breakdown of disaccharides into 
Monosaccharides by hydrolysing glycosidic bonds
Your diet contains three disaccharides, which are
Maltose produced by the digestion of starch
Lactose found in milk
Sucrose sugar you put in your tea
The disaccharidase maltase a small taste turns the disaccharide maltose into what monosaccharide
Glucose
Why do people who are lactose intolerant suffer from diarrhoea if they drink milk? 
Because lactose in the gut is not digestive which reduces the water potential of the contents and causes water to move from the epithelial cells, lining the guts into the lumen by osmosis 
Peptidase are enzymes that break down what 
Proteins and peptides by hydrolysing peptide bonds between amino acids 
What are the two main types of peptidases called?
Endopeptidases which hydrolyse peptide bonds within a polypeptide
Exopeptidases which hydrolyse peptide bonds at the terminal of a polypeptide
Some exopeptidases are called dipeptidases, because they hydrolyse peptides to produce what
Amino acids, the monomer unit of polypeptides
Where are most dipeptidases located? 
Most dipeptidase is a membrane bound and located on the cell surface membrane villi cells on the small intestine
Lipase enzymes catalyse the breakdown of what 
Triglycerides into fatty acids and monoglycerides by hydrolysis of ester bonds
Where are lipases made? 
The pancreas and secreted into the small intestine where they act
Bile salts produced by the liver are important in the digestion of lipids, because?
Because they emulsify lipids into smaller droplets 
These droplets have a bigger surface area than 1 large droplet making it easier for what?
Lipases to digest them 
Where does absorption take place?
In the stomach for example key vitamins and minerals
In the small intestines, example, 3 regions of the small intestine absorb different products of digested food
The large in testing, for example, water, vitamins, and minerals 
What are the three ways in the small intestine is adapted for absorption
Large surface area
Rich blood supply
Short diffusion pathway
