Food Flashcards
What is nutrition?
Nutrition is the way in which an organism obtains and uses food
What are nutrients?
Nutrients are chemical substances, present in food, that are used by organisms
Why are nutrients used by organisms?
- As a source of energy
- To make chemicals needed for cell or metabolic reactions
- As raw material for the growth and repair of structures in an organism
What are the 6 common elements found in food?
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
- Nitrogen (N)
- Phosphorus (P)
- Sulphur (S)
(CHONPS)
What 5 elements are present as dissolve salts in food?
- Sodium (Na)
- Magnesium (Mg)
- Chlorine (Cl)
- Potassium (K)
- Calcium (Ca)
What three trace elements are found in food?
- Iron (Fe)
- Copper (Cu)
- Zinc (Zn)
What are bio molecules?
Bio molecules are chemicals that are made inside a living thing
What are bio chemicals?
Bio chemicals are bio molecules which contain carbon
What are the 4 major bio molecules?
- Carbohydrates
- Lipids (Fats)
- Proteins
- Vitamins
What elements are found in carbohydrates?
Carbon, Hydrogen and Oxygen
What is the general ratio for carbohydrates ?
C x (H2O) y
What is the structural role of carbs?
The carbohydrate cellulose is used to form plant cell walls
What is the metabolic role of carbs?
Carbs are broke down in respiration to release energy
What use do carbs have?
To store and supply energy
How can we test for carbohydrates?
Iodine and bread
Red/Yellow to Blue/Black
What are monosaccharides?
- Smallest unit of carbs
- Sweet to taste
- Soluble in water
- Single sugar unit
What is an example of a monosaccharide?
Glucose
- Provides energy
- Found in fruits and chocolate
What is a disaccharide ?
- Two monosaccharides joined tighter
- Sweet to taste
- Soluble in water
Examples of disaccharides?
Sucrose
- Table sugar
- glucose + fructose
Maltose
- found in germinating seeds
- glucose+glucose
Lactose
- found in milk
- glucose+galactose
What are polysaccharides?
- Many units of carbs joined together
- Not sweet to taste
- Insoluble or only slightly soluble in water
Examples of polysaccharides?
Starch
- carb stored by plants
- e.g rice, potatoes and flour
Cellulose
- difficult to break down and is used as fibre
- used in cell walls
What elements are found in lipids?
Carbon, hydrogen and oxygen
What is the difference between fats and oils?
Fats are solid lipids at room temperature, oils are liquid lipids at room temperature
What are sources of lipids?
Butter and oil
What is the structural role of lipids?
Lipids are important food stores in plants and animals. Stored lipids can have a secondary function as heat insulation and protection of organs
What is the metabolic role of lipids?
Lipids are broken down in respiration to release energy
How do we test for lipids?
Using brown paper and butter
Lipids make brown paper translucent
What is a triglyceride?
One molecule of glycerol linked to three fatty acid molecules
What is the structure of a phospholipid?
Made of one glycerol linked to two fatty acid molecules and a phosphate
What elements are in protein?
Carbon, hydrogen, oxygen and nitrogen. Sometimes phosphorus and sulfur
What are sources of protein?
Meat, eggs and nuts
What is the structural role of proteins?
Keratin is found in strong skin and hair
Myosin is found in muscles
What is the metabolic role of proteins?
Proteins are used as enzymes to control reactions and as antibodies to fight infection
How can we test for proteins?
Biuret reagent in egg white
Colour change from blue to violet
What are proteins composed of?
Amino acids
How many different amino acids are found in proteins?
20
What is the bind between amino acids called?
A peptide bond
What is a group of more than 20 amino acids called?
A polypeptide
What is a long polypeptide called? (200 amino acids)?
A protein
What are vitamins?
Vitamins are complex carbon based substances that the body cannot make. They are only needed in small amounts
Is vitamin c water soluble?
Yes
What are sources of vitamin c?
Veg and fresh fruit
What is the metabolic role of vitamin c?
To help healing and immune system
What is a deficiency in vitamin c?
Scurvy (seen in bad teeth and gums)
Is vitamin d water soluble?
No, vitamin d is fat soluble
What is a source of vitamin d?
Made in skin through UV rays
What is the metabolic role of vitamin d?
To help absorb calcium for healthy bones and teeth
What is a deficiency in vitamin d?
Rickets in children or osteomalacia in adults (weak, deformed, brittle bones)
Why are minerals needed?
- To form bone and cement between cell walls (Ca)
- To make muscle (N,S)
- To form body fluids (tears, saliva, plasma)
- To form bio molecules like haemoglobin
What is an example of a mineral that can be found in plants and animals, what is its source and its use?
Calcium,
Found in the salts in soil and helps bind cell walls
Found in milk and cheese and makes healthy teeth and bones
What is the most abundant chemical in living things?
Water
How much mass does water make up in plants and animals?
60% in humans and 90% in animals
What is the universal solvent?
Water
Why is water essential for life?
- The liquid where all metabolic reactions take place
- Provides the basis for transport systems in organisms
What importance does water have to living things?
- Component of cytoplasm and body fluids
- Good solvent
- Good absorber of heat and temperature regulator
What are anabolic reactions?
Anabolic reactions convert smaller molecules into larger ones
Anabolic reactions require enzymes and use energy
E.g photosynthesis carbon dioxide and water to glucose
What are catabolic reactions?
In a catabolic reaction, a complex molecule is broken down into simpler ones
Catabolic reactions release energy and require enzymes
E.g Respiration , glucose is broken down, creating energy
