B6 Flashcards
What is a balanced diet? What does it contain?
A balanced diet contains all seven types of nutrients in the correct amounts and proportions
Carbohydrates
Proteins
Fats
Vitamins
Minerals
Fibers
Water
What is the dietary importance and main source of: carbohydrates
Main source:
Bread, pasta, potato, cereal, flour
Uses:
- Glucose travels to cells to release energy for metabolic reactions (17j/kg)
- Respiration/chemical reactions in cells
- extra carbs -> fats that are sorted in hips, legs and stomach to use later
What is the dietary importance and main source of: fats
Main source:
Butter margarine, oil, milk, cheese, meat, avocado, egg yolk
Uses:
‘Emergency’ energy source
Stores energy (39J/kg)
Insulation
Makes cell membranes
What is the dietary importance and main source of: proteins
Main source:
Meat, fish, eggs, beans, lentils, soy, cheese, milk
Uses:
Making cells
Repairing cells
Enzymes
Haemoglobin, keratin, etc.
What is the dietary importance and main source of: vitamins (limited to C and D)
VITAMIN C
Main source:
Citrus, raw vegetables
Uses:
Gum and tooth health
Collagen
Tissue repair
VITAMIN D:
Main sources:
Milk, butter, egg yolk, sunlight
Uses:
Helps calcium be absorbed
Strong bones and teeth
What is the dietary importance and main source of: minerals (limited to calcium and iron)
CALCIUM:
Main sources:
Milk/dairy in general, green leafy vegetables, bread
Uses:
Strong bones and teeth
Blood clotting
Healthy muscles
IRON;
Main sources:
Liver, red meat, egg yolk, dark leafy vegetables, beans, nuts
Uses:
Making haemoglobin
What is the dietary importance and main source of: fiber (roughage)
Main sources:
Plants, fruits, vegetables, brans of grains, whole meal bread, beans, nuts, brown rice
Uses:
Slows digestion -> we feel full
Absorbs water in bowels
Softens stool
Helps digestive system produce good bacteria
Makes digestive muscle do work so they move food
What is the dietary importance and main source of: water
Main source:
Water
Uses:
Solvent -> all chemicals reactions in the body
Dissolves + transport nutrients
Regulates temp
Protects organs
Maintains blood pressure
How does age, gender or pregnancy affect dietary needs?
AGE:
Children need less energy/food (small size)
Adults need more energy/food
Teenagers need even more energy/food (period of fast growth)
GENDER:
Males need more energy/food than females
Pregnant/breastfeeding women:
More energy to ensure enough calcium and iron for the baby
What causes malnutrition?
Not eating a balanced diet
What causes starvation?
If not enough food is eaten for the body to function, there is a chance you may die from starvation
What causes constipation?
Not enough fiber in you diet softens your stool too much
What causes coronary heart disease?
Fat in animal food -> saturated fat
Fat deposits build on the inside of arteries -> makes them stiffer and narrower
If it happens to coronary arteries -> not enough blood to the heart -> heart doesn’t have enough oxygen -> can’t work properly
If it becomes a blood clot -> heart attack
What causes obesity?
When you take in more energy that you use and it is stored as fat
Too much fat -> obese
Higher risk of heart disease, stroke, diabetes
What causes scurvy?
A deficiency in vitamin C
Causes bleeding gums, pain in joints + muscles, anaemia (decrease in red blood cells), swelling, exhaustion
What causes rickets?
A deficiency in vitamin D
Softer and therefore deformed bones, delayed growth, pain in spine/pelvis/legs, muscle weakness
What causes anaemia?
A deficiency in iron can cause for there to not be enough red blood cells, so tissue cannot get enough oxygen -> fatigue
What causes kwashiorkor?
Lack of protein
Underweight but having a large belly
Infections
Failure to grow muscle mass
Loss of muscle mass
What causes marasmus?
Severe shortage of protein and energy
Lack of calories
Cannot maintain normal body functions
Looking wasted and emaciated
Define ingestion
Taking substance into the body through the mouth
Define digestion
The breakdown of large, insoluble food molecules into small water soluble molecules using chemical and mechanical processes
Define mechanical digestion
The breakdown of food into smaller pieces without chemical change to the food molecule to that the food can fit through the digestive system
Define chemical digestion
Breakdown of large insoluble molecules into small soluble molecules
Breaking chemical bonds so that useful chemicals can be released and dissolved in the bloodstream
Define absorption
The movement of digested food through the walls of the intestines -> blood
Define assimilation
The movement of digested food molecules into the cells of the body where they are used
Define egestion (also called elimination)
Passing out of food that has not been digested as faeces through the anus
What is the alimentary canal?
Part of the digestive system that food travels through
Identify the organs of the digestive system
Mouth (teeth, tongue, salivary glands)
Pharynx
Epiglottis
Esophagus
Stomach
Liver
Gallbladder
Pancreas
Large/small intestines
Appendix
Rectum
Anus
What is the function of the: Mouth
Ingestion
Physical digestion (teeth)
Chemical digestion (salivary glands -> saliva (made of water, mucus,amylase (carbohydrase)))
Tongue rolls food into bolus -> slides down esophagus (mucus)
What is the function of the: pharynx
Region at the back of the throat where the trachea and esophagus divide
What is the function of the: epiglottis
Flap of tissue at the back of the throat that prevents food from entering the lungs
What is the function of the: esophagus
Tube that connects the mouth to the stomach
Peristalsis -> movement of muscles to move food
What is a sphincter
Muscles that stay contracted until substances need to pass through (one between esophagus and one at anus)
What is the function of the: stomach
Hydrochloric acid -> attacks the bad bacteria (microbes)
Protease enzymes (pepsin) -> chemically digest proteins -> amino acids, functions at high acidities
Muscles -> contract and relax to grind and mix the food inside stomaching -> churning
Mucus -> protect the stomach from acid by producing a lining
Gastric juice -> HCl + mucus + food and enzyme solution
What is the function of the: small intestine
Small soluble food molecules are absorbed into the bloodstream
To do this it has:
Large surface area
Thin wall
Good blood supply
(Also it has a smaller diameter but is longer than the large intestine)
2 substances secreted into the duodenum (start of small intestine) for protection against gastric juices:
Mucus -> lining
Bile -> neutralises acid and emulsifies fat (physically digest to make higher surface area)
How are the 3 food types digested in the small intestine?
Carbohydrates:
Carbohydrase secreted by pancreas into duodenum -> breaks bonds to makes simple sugars
Proteins:
Trypsin (protease) is secreted by pancreas into duodenum -> breaks bonds to make animo acids
Lipids/fats:
After emulsification -> lipase secreted from pancreas into duodenum -> bonds break and make fatty acids and glycerol
Simple products then absorbed into bloodstream in the ileum (second part of small intestine)
What is the function of the: vili in the small intestine
Vili -> bumps on the surface of the small intestine
Helps with absorption
Walls are one cell thick (fast diffusion)
Each has capillaries (blood can absorb the simple molecules quickly)
Bump structure -> more surface area
What is the function of the: large intestine
To absorb excess water that is mixed with the waste food to prevent dehydration
What is the function of the: rectum and anus
Rectum store faeces
Anus blocked by sphincter
Relax -> faeces passes out through egestion
Identify the types of human teeth
Look at diagram
Central incisors (front teeth)
Latent incisors
Canine
1st premolar
2nd premolar
1st molar
2nd molar
3rd molar
Describe the structure of human teeth
Crown (the part that sticks out)
Neck (the ‘transition point’ from out -> in the gums)
Root -> in the gums
Enamel (outer layer)
Cement (outer layer in gums)
Dentine (under enamel and cement)
Gum
What are the functions of the different types of teeth?
Canine:
Sharp and pointed teeth -> bite and tear food
Incisors:
Small rectangular shaped teeth -> cutting food
Premolars:
Behind canines -> grind soft food
Molars:
Behind premolars -> grind hard food
How does plaque and tartar form the teeth?
Bacteria mixes with saliva and forms a sticky film
First called plaque (is easy to remove (brush your teeth))
Later hardens into tartar (which cannot be removed by brushing)
How is a cavity formed?
The bacteria in the plaque can feed off of the sugar
Use it in respiration and turns it into acid which dissolves the enamel makes its way into the dentine, which could cause a cavity
What are way to prevent cavities?
- Moderate sugar intake -> teeth will be less at risk for cavities (at most 2 per day with meals)
- Brush your teeth at least x2 a day with fluoride toothpaste which make teeth more resistant to decay
-> regular brushing removes plaque and prevents gum disease/decay - Make regular dentist visits
What is the function and production place of: carbohydrase
Production:
Amylase -> In mouth in salivary glands
Other carbohydrase -> In pancreas and used in small intestines
Function:
Break bonds in carbohydrates -> starch -> simple sugars
What is the function and production place of: protease
Production:
Pepsin -> stomach (made to work in high acidity)
Trypsin-> made in pancreas, works in small intestine
Function:
Chemically breaks bonds in protein -> amino acids
What is the function and production place of: lipase
Production:
Pancreas and small intestine (works in small intestine)
Function:
Chemically breaks down fats/lipids into fatty acids and glycerol
What is the function of hydrochloric acid in the stomach?
Attack microbes that may have accidentally swallowed
Gives low pH (high acidity) for pepsin to work in
Why is the low pH of hydrochloric acid so important?
Denatures harmful microorganisms in food
Gives optimum pH for protease activity
What is the function of bile?
Bile -> alkaline
Neutralises the acid from gastric juices so that the walls of the small intestine are protected and other enzymes can work at their optimum
How does bile contribute to the digestion of fat?
Bile emulsifies fat
Separates it into small pieces and evenly distributed it among the enzymes
Creates a larger surface area for lipase to digest
Describe the structure of a villus
Use diagram from notes
(Outside -> inside)
Cell lining
Lacteal
Capillary
Blood approaches one side and leaves on the other
What do capillaries and lacteals do in villi?
Lacteal -> main route drainage of glycerol and fatty acids in the form of lymph -> returns to systemic circulation via thoracic duct
Capillaries -> absorb small molecules (amino acids and simples sugars) and sends them to the liver
