Nutrients and Enzymes Flashcards
What are nutrients
Nutrients are CHEMICAL SUBSTANCES in food that provide energy and materials needed by our body.
Role of water in HUMAN
- is the solvent in which chemical reactions take place
- is an essential component of cells, tissue fluids, digestive juices and blood.
- helps control body temperature
- helps to transport dissolved substances around the body
Role of water in PLANTS
- is essential for photosynthesis
- helps keep plant cells turgid and plant upright
- is needed for the transport of mineral salts up the xylem
- is needed for the transport of food substances from the leaves to other parts of the plant
Condensation reaction
A chemical reaction in which 2 simple molecules are joined together to form a larger molecule, with the removal of one molecule of water .
Hydrolysis reaction
Reaction in which a water molecule is needed to break up a complex molecule into simple molecules.
Fucntion of carbohydrates
- to provide energy for cell activities
- to form supporting structures (e.g. cell wall)
- for conversion into other organic compounds (e.g. amino acids and fats)
- to form nucleic acids (e.g. DNA)
- to synthesise lubricants
- to synthesise nectar in flowers
Why do we need food
Nutrients in food:
- provide energy
- supply raw materials to make new protoplasm
- help us stay healthy
Function of fats
- a source and store of energy
- act as an insulating material to prevent excessive heat loss
- are a solvent for fat soluble vitamins and some hormones
- form the main part of cell membranes
- help reduce water loss from skin surface
Functions of proteins
Synthesise:
- hormones
- antibodies
- new protoplasm
- enzymes
Define catalyst.
A substance which alters or speeds up a chemical reaction without itself being chemically changed at the end of the reaction.
Define Activation energy
Energy needed to start a chemical reaction
