Digestive System Flashcards
Name the types of nutrients a human requires to remain healthy
Vitamins, minerals, proteins, carbohydrates, fats and water
What are vitamins used for in the body ?
To heal wounds and boost your immune system
What are minerals used for in the body ?
To keep your bones, muscles, heart and brain working properly
What are proteins used for in the body ?
helps repair and build your body’s tissues, allows metabolic reactions to take place and coordinates bodily functions
What are fats used for in the body ?
store energy, insulate us and protect our vital organs
What is water used for in the body ?
help regulate temperature and maintain other bodily functions
What are carbohydrates used for In the body?
the main source of energy for your body’s cells, tissues, and organs
What is the role of the digestive system?
breaks nutrients into parts small enough for your body to absorb and use for energy, growth, and cell repair
What is the buccal cavity?
The mouth
What elements does the amino group in an amino acid consist of?
One nitrogen and two hydrogens
What elements does the alpha carbon group in an amino acid consist of?
Two carbons and a nitrogen
What elements does the carboxylic acid group consist of (including bonds)
A carbon double bonded to an oxygen with an hydroxide group (OH)
How many different amino acids are there?
20
What bond is formed between two amino acids?
Peptide bond
What is produced when two amino acids bond together (2 things)
Dipeptide and water (H2O)
What type of reaction happens when two amino acids bond together?
Condensation
What is the primary structure of a protein
A sequence of amino acids held together by peptide bonds
What is the secondary structure of a protein
A specific folding of the primary structure held together by hydrogen bonds
What two types of folding do you get in the secondary structure?
Alpha helix, beta pleated sheet
What is the quaternary protein structure ?
2 or more protein molecules coming together to form a functioning protein
Name the two types of nutrient used by humans as a source of energy
Carbohydrates and lipids
Why does starch need to be digested?
Because it’s a large molecule and can’t go through a cell membrane until sufficiently hydrolysed
What processes releases ATP
Respiration
What enzyme hydrolyses starch
Amylase
What three glands produce amylase
Salivary gland, pancreas and the ilium wall (small intestine)
What is the chemical formula of glucose
C6H12O6
Are there any differences in the chemical formula for glucose, galactose and fructose?
No
What is the difference between alpha and beta glucose
Alpha glucose has a hydrogen on top of the OH bond on the right side and beta is flipped having the OH bond on top of the hydrogen bond on the left side
Where can beta glucose be found ?
Cellulose
What disaccharide do you get when you join two glucose molecules together and what product is left over
Maltose with water left over
What disaccharide do you get when you react glucose and fructose together and what other product is produced
Sucrose with water also produced
What disaccharide do you get when you react glucose and galactose together and what product is also produced
Lactose with water also produced
What are polysaccharides
Multiply sugar units
What organisms storage molecules are starch and glycogen (animal or plant)
Glycogen-animal
Starch-plant
Why are starch and glucose good storage molecules?
Because it’s a branched molecule which allows it to be highly soluble
Name three polysaccharides
Glycogen, starch and cellulose
What bond joins polysaccharides together
Glycosidic bonds
What is starch broken down into and by which enzyme?
Amylase, it’s broken into maltose
What is maltose broken down into
Alpha glucose
What enzyme hydrolyses maltose ?
Maltase
How many sugar units is starch broken down into
2 sugar units
What hypotheses is used to describe how starch and other substrates are broken down
Lock and key
Name four places carbohydrates are digested
Mouth, oesophagus, stomach, small intestine
Where is pepsin made
Stomach
Where is Pepsins place of action
Mouth and stomach
What is pepsins substrate
Protein
What is pepsins product
Polypeptides
What is pepsins optimum PH
2
Where is Enterokinase made
Pancreas
Where is Enterokinase place of action
Small intestine
What is Enterokinase substrate
Protein
Where is trypsin made?
Pancreas
Where is trypsin’s place of action
Small intestine
What is trypsin’s substrate ?
Protein (polypeptide)
What is trypsin’s optimum PH
9.0
Where is Dipeptidases place of action
Small intestine
What is Dipeptidases substrate
Protein (dipeptide)
What is Dipeptidases optimum PH
5.5
What enzyme breaks down protein
Endopeptidase
What enzyme breaks down polypeptides
Exopeptidase
What enzyme breaks down dipeptides
Dipeptidase
What are dipeptides hydrolysed into
Amino acids
Where is endopeptidase active
In the stomach
How does endopeptidase help other enzymes further hydrolyse a molecule
By creating lots of “ends”
Where is exopeptidase active
The small intestine
Why is pancreas juice alkaline
To neutralise the stomach acid
Where are Dipeptidases found
On the wall of the small intestine
Why does mucus line the stomach wall
To prevent pepsin digesting the wall of the stomach
What is pepsins inactive enzyme called
Pepsinogen
What are 3 symptoms of peptic stomach ulcers
Heartburn, bloating, unexplained weight loss (also burning in upper abdomen, dark stools, nausea and vomiting)
What is trypsin’s inactive enzyme
Trypsinogen
What does bile do to fat
Emulsifies the fat globules
Where is bile made?
The liver
Where is bile stored?
The gallbladder
Bile emulsifies lipid. What does this mean?
It breaks up large fat molecules (it is not an enzyme though and NOTHING gets hydrolysed)
Why is bile alkaline?
To neutralise the stomach acid
Where is lipase made?
Pancreas, mouth and stomach
Where are lipids digested
Small intestines
What products do you get from hydrolysing lipids
One glycerol and 3 fatty acids
What part of lipids is hydrophobic
Fatty acid tails
What part of lipids are hydrophilic
Glycerol
What happens when you mix lipids and water
Micelle forms
What enzyme hydrolyses lipids
Lipase
What happens to an enzyme after optimum PH has passed
The enzyme denatures
What happens if the PH is too high for an enzyme
The enzyme denatures
What is meant by the “denatured enzyme”
A permanent change in the tertiary structure of an enzyme causing hydrogen bonds to break
What happens when en enzyme denatures ( rate of reaction and bonds )
The rate of reaction is slowed and hydrogen bonds break
What does a competitive inhibitor do ?
Slow down the rate of reaction
What happens when a competitive inhibitor binds to the active site and not the enzyme?
The enzyme can not catalyse the reaction of bind to the active site
What happens when a non competitive inhibitor binds to the allosteric site (the other active site)
The inhibitor causes the enzyme and active site to change shape making the substrate unable to bind to the active site
What needs to be on the wall of the gut to cause peristalsis?
Mucus for lubricant
What is serosa
The outer covering of the gut (strong connective tissue)
What are the muscle layers in the oesophagus for ?
Contraction and relaxation of the muscle to cause peristalsis
What does the submocosa contain
Connective tissue, nerve tissue, blood vessels, elastic tissue and lymph vessels
What does mucosa contain ?
Goblet cells which produce mucus and enzyme secreting cells
Where is gastric juice produced
Gastric pits
What do chief cells produce
Pepsinogen
What do Oxyntic/ parietal cells produce
Hydrochloric acid
What is folded to create villi
Mucosa
What are between the villi
Intestinal glands (crypts of leiberkuhn)
How are the villi adapted for the absorption of digested food ?
- large surface area
- short diffusion distance
- a diffusion gradient
Why does the large intestine wall have thick muscle
To push drier food along the gut
