B4 Flashcards
What does enzyme mean
proteins that function as biological catalysts.
What is the active site
The active site is a small region on an enzyme where substrates bind and undergo a chemical reaction.
What does substrate mean
a molecule that binds to an enzyme and undergoes a chemical reaction, resulting in the formation of products. Examples include sugars, amino acids, e.t.c.
Why is the active site important to an enzyme
Accelerate chemical reactions
Maintain high substrate specificity and catalytic efficiency
What are fats, carbohydrates, and proteins
organic molecules that are primarily made of carbon atoms. They’re also mostly naturally occuring in living organisms
Elements present in carbohydrates, fats, and proteins
carbon, hydrogen, and oxygen
Why isn’t carbon dioxide an organic
There’s no hydrogen presence in carbon dioxide and it’s not derived from living matter
What is organic
- contain carbon
- derived from a living matter (formed from the remains or byproducts of living organism)
What are macromolecules
large molecules
What are large macromolecuels made from
smaller molecules called monomers
Examples of macromolecules
starch and glycogen from glucose
proteins from amino acids
fats and oils from fatty acids and glycerol.
What monomers makes starch and glycogen
glucose
What monomer makes proteins
amino acids
What monomers make fats and oils
fatty acids and glycerol
What is the main source of energy for all living organisms
carbohydrates
Function of proteins in living organisms
to build and repair muscles and bones and to make hormones and enzymes.
What are the two monomers of lipids or fats
Fatty acids and glycerol
Main function of lipids or fats
energy storage, insulation, and portection
How to test for starch
Add iodine solution if it turns blue black there’s starch presence
How to test fo reducing sugars e.g. glucose, fructose, e.t.c.
Add equal volume of benedict’s solution to the test subject shake Bring gently to the boil (or place the tube in a beaker of boiling water) for 3 mins.
initial blue colouration of the mixture turns green → yellowish → orange → finally a brick-red
What does the color change in benedict’s test show us
the colour changes show an INCREASE in the amount of glucose present.
How to test for proteins
Use biruets test add equal amount of sodium hydroxide to the test subject Add 2-3 drops of copper sulphate solution slowly down the side and then mix.
A positve test result should be A blue ring appears on adding the copper sulphate.
A purple colour develops slowly on mixing.
How to test for lipids
a emulsion test. Add 2cm3 of ethanol to your sample.
Dissolve the lipid in food by shaking vigorously.
Add an equal volume of cold water.
Positive test result
A cloudy white suspension indicates the presence of lipids (this is called an emulsion).
Why is water such a good solvent
Because its polarity and ability to form hydrogen bonds, water makes an excellent solvent, meaning that it can dissolve many different kinds of molecules.
Why is water essential for a balanced diet
Water is the medium for cellular processes like metabolism, nutrient transport, and waste removal.
Water helps dissolve nutrients, soluble fiber, and minerals for absorption.
Water regulates body temperature through sweating and evaporation.
What is waters role in metabolic processes
It helps dissolve nutrients for absorption
Transports nutrients to cells
What can a balanced diet qualify as
A diet where all food groups are preasent such as. Carbohydrates: 55-65% of daily energy intake
Protein: 10-15% of daily energy intake
Fat: 20-30% of daily energy intake
Fiber: 18-30g per day
Water: at least 8 cups (1.9L) per day
Essential nutrients: vitamins, minerals, and micronutrients
Variety: include all food groups: fruits, vegetables, whole grains, lean proteins, and healthy fats
What components does a balanced diet have
carbohydrates, fats, proteins, vitamins (C and D), mineral salts (calcium and iron), fibre and water.
Importance and sources of carbohydrates
It Provides energy for the body and brain function
Bread, pasta, and rice
Importance and sources of fats
Provides energy for the body and vitamin abosroption
Animal products, nuts, and seeds
Importances and sources of proteins
build and repair tissues, produce enzymes and hormones
Animal products, vegtables
Importances and sources of vitamin C
It improves immune function, collagen production
Sources of vitamin C
Citrus fruits and berries
Importance and sources of vitamin D
Bone health, immune function
Sources of vitamin D: sunlight, fatty fish, fortified dairy
Importance and soruces of iron
iron is important bc. oxygen transport and immune support
Sources of iron red meat
Importance and sources of calcium
bone health and muscle function
sources of calcium: diary such as milk and chesse
Importance and sources of fibre
healthy digestion, bowel movements,
sources of fibre: whole grains, fruits, vegetables,
What is scurvy, what are symptoms of it, and how to treat it
Scurvy is a disease caused by a lack of vitamin C
Symptoms : Fatigue, weakness, and bleeding gums,
Treatments
Vitamin C supplements or dietary changes to include vitamin C-rich foods like citrus fruits, berries, and leafy greens
What is rickets, what are symptoms, and how to treat it
Rickets is a disease that affects bone development in children, causing soft and weak bones. It is caused by a lack of vitamin D and calcium in the diet.
Symptoms Bow legs, stunted growth, soft skull bones,
Treatments vitamin D and calcium supplements, dietary changes to include vitamin D-rich foods like fatty fish, fortified dairy, and sunlight exposure
What are enzymes
as proteins that are involved in all metabolic reactions, where they function as biological catalysts
Examples of enzymes controlloed metabolic reactions
Amylase: Breaks down starch into simple sugars (glycolysis)
Protease: Breaks down proteins into amino acids (protein synthesis)
How can temperatures affect enzymes
they all have an optimum temperature they work best at, in a higher temperature there may be a higher enzyme activity to a point but after the optimum temperature the enzyme will denature. In a lower temperature there will be a decrease in enzyme acitivity and then they become inactive in very low temperatures.
How can pH affect enzymes
Most human enzymes work best at pH of 7. An increase in pH decreases enzyme activity and then denatures it. A decrease in pH decreases enzyme activity, and then they become inactive
Brief overview of enzyme action
Substrate binds to active site, forming enzyme-substrate complex. Enzyme facilitates chemical reaction, converting substrate to product
roduct is released from active site
Enzyme returns to its original shape, ready to bind new substrate
What is a substrate
the molecule that the enzyme acts on
Why is the active site important that it doesn’t denature.
The active site is shaped to fit the substrate, ensuring efficient binding and catalysis
What is denaturing
when the active site loses its shape
More complex explantion of how temperature affects enzymes
Increase in temperature
Increases kinetic energy of molecules
Increases frequency of effective collisions between enzyme and substrate
Enhances enzyme activity (up to a point)
Denatures enzyme (above optimum temperature)
Loss of shape and fit
Enzyme becomes inactive
Decrease in temperature:
Decreases kinetic energy of molecules
Decreases frequency of effective collisions
Decreases enzyme activity
Enzyme becomes inactive (at very low temperatures)
What part of the digestive system is in charge of ingestion
Mouth: food intake, chewing, mixing with saliva
Esophagus: food transport to stomach
What is ingestion
the taking of substances, e.g. food and drink, into the body
What part of the digestive system is in charge of digestion
Mouth: saliva breaks down carbohydrates
Stomach: gastric juice breaks down proteins and fats
Small intestine: pancreatic juice and intestinal enzymes break down carbohydrates, proteins, and fats
What is digestion
the breakdown of food
What part of the digestive system is in charge of absorption
Small intestine: nutrients absorbed into bloodstream
Villi and microvilli increase surface area for absorption
What is absorption
the movement of nutrients from the intestines into the blood
What part of the digestive system is in charge of assimilation
Bloodstream: nutrients transported to cells
Cells: nutrients used for energy, growth, and repair
What is assimilation
the uptake of usage of nutrients in cells
What part of the digestive system is in charge of egestion
Large intestine: water and electrolytes absorbed
Rectum: storage of feces
Anus: elimination of feces
What is egestion
the removal of undigested food from the body as faeces
What is physical digestion
the mechanical breaking down of food into smaller pieces without chemical change to the food molecules
How does physical digestion help the absorption of food
increases the surface area of food for the action of enzymes in chemical digestion
What is chemical digestion
the breakdown of large insoluble molecules into small soluble molecules
How does chemical digestion aid absorption
it produces small soluble molecules that can be absorbed easily
What does the enzyme amylase do
breaks down starch to simple reducing sugars
What does the enzyme protease do
break down protein to amino acids
What does the enzyme lipase do
breaks down fats and oils to fatty acids and glycerol
Where is amylase secreted and where does it act
Pancrease, salviary glands
Mouth, duodenum, and small intestine
Where is protease secreted and where does it act
Pancreas, stomach
Stomach, small intestine, and duodenum
Where is lipase secreted and where does it act
Pancrease
Small intestine and duodenum
Functinon of hydrochloric acid in stomach juices that are secreted
Kills harmful microorganisms in food:
Bactericidal properties
Prevents infection and food poisoning
Provides acidic pH for optimum enzyme activity:
Maintains pH 1.5-2.5 in stomach
Optimal pH for proteases (pepsin and gastric amylase)
Activates pepsinogen to pepsin
What is bile and its functions
Alkaline mixture:
pH 7.8-8.6
Neutralizes acidity
Neutralizes acidic mixture:
Food and gastric juices from stomach
Entering duodenum
Provides suitable pH for enzyme action:
Optimal pH for pancreatic enzymes
Small intestine digestion and absorption
Role of bile in chemical digestion
Emulsifies fats and oils:
Breaks down into smaller droplets
Increases surface area
Increases surface area for chemical digestion:
Lipase enzymes can act more efficiently
Faster and more complete digestion of fats
Difference between sugars and fats for energy
Sugars are a good source of ‘instant’ energy. Because of their chemical structure they are quickly broken down into glucose, which the body can immediately absorb. Lipids (fats) are a good source of long-term energy, as they have more energy content per gram compared to carbohydrates but take longer to be digested.
Define emulsification of fats
Emulsification of fats is the process by which bile salts break down large fat droplets into smaller, more manageable particles, creating a stable mixture of water and fat called an emulsion.
What is lock and key theory
each enzyme’s active site is built for the specific substrate
3 things stomachs do for digerstion
mechanical digestion: pummels food with muscular walls to break down
chemical disgestion: produces protease enzymes and hydrochloric acid to firstly kill bacteria and create the right pH for protease to work at
function of liver
where bile is produced, bile can neutralize stomach acid and emulsify fats
functions of pancresae
they make the 3 main enazymes protease, lipase, and amylase
function of gallbladder
where bile is stores before secretion into duodenum
Why are enzymes so important
Carbohydrates, proteins and lipids in food are too large, complex and insoluble to be absorbed from the digestive system into the blood.
What goes into the large intestine
mostly things that aren’t digested by the small intestine such as the fibre and water
what are the mechanisms for absorption
diffusion into the capillary network then transported up the blood vessels
What is absorbed by the capillary and lacteral
capillary aborbs the soluble
Glucose
Amino acids
Fatty acids
Glycerol
Lacteral absorbs Fats
Overview of digestion
