Characteristics common to all living things. The Life Processes Characteristics common to all living things.

What does it mean to be alive? As we have seen, defining life hasn’t always been the easiest thing to do. For example, things like viruses appear to be alive, but they DO NOT carry out all 8 life processes. For something to be classified as living it must be able to carry out all 8 life processes. In no particular order, here are the life processes.

Nutrition The obtaining and processing of food materials. Some organisms are heterotrophs, and need to eat other organisms for energy. Others are autotrophs and are able to make their own food.

Those amazing autotrophs Most of you know that plants use light energy to create sugars through the process of photosynthesis. However, photosynthesis is not the only type of autotrophic nutrition on earth. Some types of bacteria carry out chemosynthesis. They convert chemicals with would be poisonous to us in to usable energy. Life at deep ocean hydrothermal vents is only possible because of chemosynthetic bacteria.

Transport The intake and distribution of materials throughout an organism. Complex animals, such as humans, use organ systems to carry out this life process. Single-celled organisms carry out transport using their organelles and a type of cytoplasmic streaming called cyclosis. cyclosis animation

Respiration The release of energy from food by oxidation. We need both food and oxygen to get the energy we need to carry out all of the life processes. All living things, all of them must carry out respiration 24 hours a day/ 7 days a week. Riddle…what do you call an organism that does not respire? DEAD!!

Excretion The removal of metabolic wastes from an organism. Metabolic wastes are waste products that are created within your cells. The life processes all have two things in common. They all require energy, and they all produce wastes. Urine, sweat and CO2 are all examples of metabolic wastes removed from our bodies by excretion.

Synthesis The combining of simple molecules to form a more complex molecule. Photosynthesis is the process by which plants create sugar (C6H12O6) by combining CO2 and H2O in the presence of light. Protein synthesis occurs when amino acids and bonded together to form proteins, such as hormones and antibodies. protein synthesis animation

Regulation The coordinated response by a living organism to a changing environment. Shivering when you are cold, or sweating when you are hot are both examples of regulation. In the video, they referred to regulation as “sensitivity”. Simple organisms, like amoebas will move away from areas which are too hot or too cold.

Growth The increase in the size of an organism. In humans, we reach our adult size and stop growing. In other organisms, such as trees and crocodiles, individuals will continue to grow throughout their lives. The bigger the tree (or crocodile) the older it is.

Reproduction The ability of living things to create more on their own kind. Reproduction is necessary for the species, but not the individual organism. Reproduction can be asexual (one parent) or sexual (two parents). We will learn more about this in future units.

2 more vocabulary words. While these are not technically life processes they are related. Metabolism: The sum total of all the life processes. Homeostasis: The ability of an organims to maintain a stable internal environment. An organism that does not maintain homeostasis will become sick. If it remains out of homeostasis for an extended period of time, it will die.