Heterotrophic Nutrition: Balanced Diet - Biology Form 4

Comprehensive review flashcards covering heterotrophic nutrition, balanced diets, organic and inorganic nutrients, vitamins, minerals, food groups, energy factors, and malnutrition disorders.

What is the definition of a balanced diet?

A balanced diet is one which has the quality and proportions of nutrients in order to maintain good health.

What are the four groups of organic nutrients required in a balanced diet?

Carbohydrates, proteins, lipids, and vitamins.

What are the three inorganic nutrients and dietary components required in a balanced diet?

Minerals, water, and fibre.

Which chemical elements make up carbohydrates?

Carbon, hydrogen, and oxygen.

What are four specific examples of carbohydrate sugars listed in the lecture?

Glucose, fructose, sucrose, and galactose.

In what molecular structure do carbohydrates usually exist?

They usually exist as ring(s) formed from carbon atoms bound to oxygen and hydrogen atoms.

How are carbohydrates classified based on whether they contain one, two, or many rings?

One ring is a monosaccharide, two rings is a disaccharide, and many rings are polysaccharides.

What is the primary function of carbohydrates in the human body?

Carbohydrates are used by the body for energy.

What is the most basic unit of carbohydrates?

Glucose.

What carbohydrate molecule is depicted in this chemical structure diagram?

Glucose.

What chemical elements compose proteins?

Carbon, hydrogen, oxygen, nitrogen, and small amounts of sulphur.

What monomer subunits make up long chains of proteins?

Amino acids.

Approximately how many amino acids combine in different arrangements to form different proteins?

There are about $20$ amino acids.

What are two examples of proteins found in the human body mentioned in the lecture?

Keratin and haemoglobin.

What is the primary biological function of proteins in the body?

Proteins are used for building and repairing body cells and tissues.

What malnutrition conditions are caused by protein deficiency?

Kwashiorkor and marasmus.

What basic monomer unit of proteins is shown in this chemical structure?

An amino acid.

What physical substances are collectively categorized as lipids?

Fats and oils.

What chemical elements compose lipid molecules?

Carbon, hydrogen, and oxygen.

What is the molecular makeup of a single lipid molecule?

$3$ fatty acid molecules joined to $1$ glycerol molecule.

Why are lipids insoluble in water?

Because lipids are oily.

Where are lipids stored in the human body?

Under the skin and around vital organs.

Why are lipids particularly important in the nutrition of infants?

They are essential for the development of the brains of babies.

What structural difference distinguishes the saturated fatty acid from the unsaturated fatty acid shown in this diagram?

The saturated fatty acid contains only single carbon-carbon bonds, whereas the unsaturated fatty acid contains a double bond ($C=C$) that produces a kink or bend in the carbon chain.

Which vitamins covered in the lecture are classified as fat-soluble?

Vitamin A, Vitamin D, Vitamin E, and Vitamin K.

Which vitamins covered in the lecture are classified as water-soluble?

Vitamin B1, Vitamin B2, Vitamin B3, Vitamin B5, Vitamin B6, Vitamin B7, Vitamin B9, Vitamin B12, and Vitamin C.

What is the scientific name of Vitamin A?

Retinol.

What are the two major functions of Vitamin A in the body?

It aids vision in dim light and keeps skin and mucous membranes healthy.

What symptoms or conditions are caused by Vitamin A deficiency?

Night blindness and dry skin.

What is the scientific name and primary function of Vitamin B1?

Thiamine; it helps in cellular respiration.

What deficiency disease is caused by a lack of Vitamin B1, and what are its symptoms?

Beri-beri, in which muscles become weak and painful and the nervous system is affected.

What is the scientific name of Vitamin B2?

Riboflavin.

What are the main functions of Vitamin B2 in the human body?

It is necessary for normal embryo development, helps repair damaged tissues and wounds, maintains healthy skin, hair, eyes, and the nervous system, and helps in the formation of red blood cells.

What deficiency symptoms are associated with an inadequate intake of Vitamin B2?

Blurred vision, cataract, fatigue, headaches, anaemia, gingivitis, skin lesions, growth problems, and neurological disorders.

What is the scientific name of Vitamin B3?

Niacin (nicotinic acid).

What are the biological functions of Vitamin B3?

It aids in respiration, keeps skin, hair, and the nervous system healthy, and helps the body process protein and fats.

What deficiency disease is caused by Vitamin B3 deficiency, and what are its symptoms?

Pellagra, which causes diarrhoea, scaly sores, inflamed mucous membranes, and delusions.

What is the scientific name and critical functions of Vitamin B5?

Pantothenic acid; it is critical to the manufacture of red blood cells and sex and stress-related hormones produced in the adrenal glands.

What symptoms are caused by Vitamin B5 deficiency?

Severe stress, severe malnutrition, and a burning sensation in the feet.

What is the scientific name of Vitamin B6, and what is its role in cells?

Pyridoxine; it is important for proper cell function, including helping with metabolism, creating blood cells, and keeping cells healthy.

What deficiency symptoms result from a lack of Vitamin B6?

Depression and irritability.

What is the scientific name and metabolic function of Vitamin B7?

Biotin; it helps the body metabolize fats, carbohydrates, and protein.

What are the symptoms and frequency of Vitamin B7 deficiency?

Deficiency can lead to hair loss and skin problems, but it is rare.

What is the scientific name of Vitamin B9?

Folic acid.

Why is Vitamin B9 critical for early pregnancy and cellular reproduction?

It is important for foetal development in early pregnancy, plays an essential role in brain function and mental/emotional health, and aids in the production of DNA and RNA.

What symptoms can result from Vitamin B9 (folic acid) deficiency?

Poor growth, tongue inflammation, gingivitis, loss of appetite, shortness of breath, diarrhoea, irritability, forgetfulness, and mental sluggishness.

What is the scientific name of Vitamin B12?

Cobalamin.

In which foods is Vitamin B12 mainly found, and how must vegetarians obtain it?

It is mainly found in animal products (meat, eggs, dairy, liver, kidneys, clams, and sardines); vegetarians must consume foods fortified with Vitamin B12.

What functions does Vitamin B12 perform in the body, and what does its deficiency cause?

It keeps nerves healthy, maintains normal brain function, and supports DNA and red blood cell production; deficiency leads to weakness and fatigue.

What is the scientific name of Vitamin C?

Ascorbic acid.

What are the physiological functions of Vitamin C?

It protects cells, maintains healthy skin, blood vessels, bones, and cartilage, aids in wound healing, and assists in the absorption of iron.

What deficiency disease is caused by a lack of Vitamin C, and what are its symptoms?

Scurvy, which causes swollen, bleeding gums, skin that bruises easily and takes long to heal, and severe joint and leg pains.

What is the scientific name of Vitamin D?

Calciferol.

What is the biological function of Vitamin D?

It helps regulate the amount of calcium and phosphate in the body and keeps bones, teeth, and muscles healthy.

What deficiency diseases occur due to a lack of Vitamin D in children compared to adults?

Rickets in children and osteomalacia in adults.

What is the scientific name of Vitamin E?

Tocopherol.

What are the major health functions of Vitamin E?

It helps maintain healthy skin and eyes and strengthens the immune system (the body's natural defence against illness and infection).

What nerve and muscle problems result from Vitamin E deficiency?

Loss of feeling in the arms and legs, loss of body movement control, muscle weakness, and vision problems.

What is the scientific name of Vitamin K?

Quinones.

What are the main physiological roles of Vitamin K?

It helps synthesize various proteins needed for blood clotting and the building of bones.

What are the clinical consequences of Vitamin K deficiency?

A longer time for blood to clot, external bleeding, hemorrhaging (internal bleeding), and osteoporosis (weakened bones).

What are the functions of Calcium in the human body?

Building strong bones and teeth, clotting blood, sending and receiving nerve signals, squeezing and relaxing muscles, releasing hormones/chemicals, and maintaining a normal heartbeat.

What is the clinical term for Calcium deficiency, and what are its neuromuscular symptoms?

Hypocalcemia; it causes muscle cramps and spasms, numbness and tingling in the hands and feet, seizures, and fatigue.

What skeletal and chronic health effects can result from hypocalcemia?

Osteopenia, osteoporosis, rickets, tooth decay, gum disease, abnormal heart rhythm, and memory loss.

What is the primary role of Iron in the body?

Transferring oxygen from the lungs to tissues and participating in cellular metabolism as a component of proteins and enzymes.

What clinical condition is caused by Iron deficiency?

Anaemia.

Why is it advised to avoid eating liver during pregnancy despite it being rich in iron?

Because liver contains very high levels of Vitamin A which can pose health risks during pregnancy.

Why does the human body require Iodine?

To make thyroid hormones that control the body's metabolism and promote proper brain and bone development during pregnancy and infancy.

What deficiency condition involving swelling in the neck is shown in this image?

Goitre (caused by iodine deficiency).

What condition caused by infant/childhood iodine deficiency is depicted in this historical illustration?

Cretinism.

What are the two main biological functions of Phosphorus?

It helps build strong bones and teeth and helps release energy from food.

What clinical symptom or defect is caused by Phosphorus deficiency?

Brittle bones.

What percentage of a balanced meal should be comprised of Staples?

$41\%$ of the meal.

How many portions of Staples are recommended on the food plate?

$6\text{ to }11$ portions.

What foods are categorized within the Staples food group?

Cereals, cornmeal, wheat flour, oats, starchy fruits, roots, and tubers.

What percentage of a balanced meal should Legumes make up, and how many portions are recommended?

$21\%$ of the meal ($2\text{ to }4$ portions), including beans, peas, and nuts.

What percentage of a balanced meal should Vegetables make up, and what are its two subcategories?

$11\%$ of the meal ($3\text{ to }5$ portions); divided into dark green leafy vegetables (cabbage, pak choi, lettuce, spinach) and yellow vegetables (pumpkin, carrot, peppers).

What percentage of a balanced meal should Fruits make up, and what examples are provided?

$11\%$ of the meal ($2\text{ to }4$ portions), including citrus, bananas, golden apples, and soursop.

What percentage of a balanced meal should Food from animals make up, and what items are included?

$11\%$ of the meal ($2\text{ to }3$ portions), including fish, meat, poultry, milk, eggs, cheese, and butter.

What percentage of a balanced meal should Fats and oils make up, and what foods does it include?

$5\%$ of the meal ($1\text{ to }3$ portions), including oils, butter, margarine, cakes, and biscuits.

Why do men generally have a higher energy requirement than women?

Men have more muscle mass and weigh more than women.

Why do pregnant women require more energy than non-pregnant women?

Extra energy is needed for the growth of the foetus and preparation for breastfeeding.

How do energy requirements change from childhood through to old age?

Energy requirements increase up to the age of $18$, and then decrease as a person gets older.

How does level of physical activity affect human energy requirements?

People with active lifestyles require more energy than those with mostly sedentary lifestyles.

What does the word 'malnutrition' literally mean?

"Bad nutrition".

What are the two main types of malnutrition?

Under-eating (not enough is eaten) and over-eating (too much is eaten).

What is starvation, and what are its three primary signs?

Starvation occurs when not enough food is eaten to supply daily energy needs; signs include weight loss, reduced resistance to diseases, and reduced growth and development.

What dietary deficiency causes marasmus and kwashiorkor?

Not eating enough protein.

What are the clinical signs and symptoms of marasmus and kwashiorkor?

Being severely underweight ($< 60\%$ of weight for age), thin arms and legs, reduced growth, reduced resistance to infection, oedema (swelling of tissues), thin/sparse/weak hair, rough dry skin, and shrunken facial features (old appearance).

What protein deficiency disease, marked by a swollen abdomen and tissue oedema, is visible in this child?

Kwashiorkor.

What is anorexia, and which demographic is most commonly affected?

The voluntary refusal to eat; it is most commonly found in teenagers (girls more than boys).

Why is anorexia classified as a psychological illness?

Because the refusal to eat results from poor self-image, where the individual thinks they are fat even when they are not.

What is bulimia?

A psychological condition most common in teenagers where an individual eats large quantities of food and then regurgitates to avoid gaining weight.

What causes obesity, and what physiological change occurs in the body?

It results from eating too much food, especially fatty foods; excess fat accumulates in the body and body mass increases to well above normal.

What is diabetes?

A metabolic disease in which a person has high blood sugar.

What is the physiological cause of Type I diabetes compared to Type II diabetes?

In Type I diabetes, the pancreas does not produce enough insulin; in Type II diabetes, the body cells do not respond properly to the insulin that is produced.

What dietary habit directly increases the risk of diabetic complications mentioned in the lecture?

Eating too much sugary foods.

What are cardiovascular diseases, and what dietary excesses cause them?

Diseases of the heart and blood vessels caused by eating too much carbohydrates and fats.

What is the difference between coronary heart disease and a stroke?

In coronary heart disease, blood supply to the heart is blocked by a fat build-up in the coronary artery; in a stroke, blood supply to the brain is blocked by fat build-up in blood vessels leading to the brain.

What cardiovascular condition involving the build-up of plaque inside an artery wall is depicted in this diagram?

Atherosclerosis.