Science 9Organic Matter Synthesized by Plants & Animals

Plants and animals can synthesize or create some organic substances which are important to life → carbohydrates, lipids, proteins and nucleic acid.

Carbohydrates

we need them but we have to eat them → e.g. grains, rice, potatoes, fruits, pasta, breads

plants can make them… from atoms of carbon, hydrogen and oxygen

  • some are simple molecules like glucose, fructose and sucrose (sugars)
  • some are complex molecules such as starch, cellulose and glycogen

glucose (essential sugar for cellular respiration in humans) is synthesized or created by green plants in the process of photosynthesis

Lipids

include fats, oils and wax

made from atoms of carbon, hydrogen and oxygen

fat molecules are made up of fatty acids and glycerol (important part of cell membranes)

produced by plants and animals

  • in animals – our skin produces oils and our body stores food as fat
  • in plants – they produce oils and fats in seeds (e.g. peanuts, corn, canola seeds)

Proteins & Amino Acids

made up of carbon, hydrogen, oxygen and nitrogen

proteins are found in foods such as meat, fish, eggs and dairy

they are important for growth and repairof tissue in our bodies, and as a source of energy

they are the main components of enzymes… which are the catalysts that control chemical reactions in organisms

proteins are made up of building blocks called amino acids, arranged in sequence

  • each protein has its own number and arrangement of amino acids… between 40 and 500 amino acid units!
  • 20 different kinds of amino acids are common in protein molecules
  • green plants convert glucose into amino acids
  • an amino acid you might recognize is insulin

amino acids make up 75% of the human body→ they are essential to nearly every bodily function… and nearly every chemical reaction

10 essential amino acids must be ingested every day → unlike fats and starches they are not stored for later use

Nucleic Acids

they are the largest complex molecules found in living organisms

found in cells, there are 2 important types:

  • DNA – deoxyribonucleic acid
  • RNA – ribonucleic acid

composed of phosphate, a simple sugar (deoxyribose or ribose) and nitrogen-containing bases

responsible for transmitting characteristics from parent to offspring (heredity), and controlling cell activity