Chapter Text
Six Characteristics of Living Things
1. Having one or more cells
What are cells?
- Cells are the basic building block of life.
- Smallest unit that can perform all life processes
- Covered by a Cell Membrane
- Contain Cytoplasm and Deoxyribonucleic Acid (DNA)
Multi-Celled Organism - Different kinds of cells perform specialized functions
Single-Celled Organism - Different parts of the cell perform different functions
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2. Stimulus and Response to change
Stimulus - Something that affects the activity of the organism
Response - How an organism reacts to a stimulus
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3. Reproduction
- All living things need to be able to make new living things — or their species will cease to exist
Sexual Reproduction - Two parents produce offspring that will share characteristics of both parents. Most plants and animals produce this way
Asexual Reproduction - A single parent produces offspring that are identical to the parent
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4. Have DNA
DNA/Deoxyribo-nucleic Acid - What makes everything on Earth unique
Heredity - When organisms reproduce, they pass copies of their DNA to offspring
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5. Use energy
- The ultimate source of energy is the sun
Metabolism - The total of all chemical activities that an organism performs
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6. Grow and Develop
- All living things, one cell or more, grow during periods of their lives
Single-Celled Organism - The cell gets larger and divides, making other organismsI
Multi-Celled Organism - The organism gets larger by the number of cells increasing
Use GREDSAC to help you remember!
Grow and Develop
Reproduce
Energy
DNA
Stimulus and Response
All Living Things
Cell
The Necessities of Life
1. Water / H2O
- Your body is made mostly of H2O
- Cells are about 70% H2O
- Most chemical reactions involving metabolism require H2O
- Can survive only about 3 days without H2O
- Remember… living things get H2O from both fluid and food
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2. Air
- Mixture of several different gases, including Oxygen (O2) and Carbon Dioxide (CO2)
- Organisms living on land get O2 from the air
- Use O2 when releasing energy from food
- Most get O2 from clean air
- Organisms living in water take in dissolved O2 from the H2O or come to surface for O2
- Green plants, algae, and some bacteria need CO2 in addition to O2… They produce food and O2 by photosynthesis
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3. Place to live
- Contains all things needed for survival
- Space changes for each living organism
- Space on Earth is limited, so often organisms compete with each other for food, water, and other needs
- Many animals will claim a space and try to keep other animals away
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4. Food
- Gives organisms energy and the raw materials needed to carry on life processes
- Get nutrients to replace cells and build body parts
- Grouped into three different food groups based on how they obtain their food
Producers - Organisms that can make it’s own food using energy from it’s surroundings
Consumers - Organisms that eat other organisms or organic matter
Decomposers - Organisms that get their energy by breaking down the dead organisms and consuming their nutrients ; clean our environment
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5. Putting it all together
- All organisms need the nutrients in food
- Nutrients are made up of molecules
Molecules - Substances made by combining two or more atoms
Compound - Molecules made by different kinds of a atom
Molecules found in living things are usually made if different combinations of six elements : Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur : CHNOPS
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6. Proteins
- Made up of Amino Acids
- Needed to build and repair body structures
- Regulates processes in the body
- Needed EVERY day; cannot be stored
- Enzymes, type of protein, start or speed up chemical reactions in cells
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7. Carbohydrates
- Molecules made up of sugar
- Source of energy
- Energy storage
- Organism’s cells break down carbohydrates to release the energy stored in them
- Two kinds: Simple and Complex
Simple Carbohydrates - Made up of one sugar molecule or a few sugar molecules linked together
Complex Carbohydrates - Made up of hundreds of sugar molecules linked together. When the body has extra sugar than it needs, it stores the sugar as complex carbohydrates
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8. Lipids
- Compounds that cannot mix/dissolve in water
- Some store energy
- Some form the cell’s membrane — which helps protect the cell and keeps the interal conditions stable
- Two Kinds: Phospholipids and Fats and Oils
Phospholipids -
- Molecules that form much of the cell membrane
- The head is attracted to H2O
- The tail is not attracted to H2O
- When in H2O, the tails come together, and the heads face out the H2O
Fats and Oils -
- Store energy
- Most fats are solid, and most oils are liquids
- When you use up the energy from the carbohydrates, then it moves to the fats
- Most lipids stored in animals are fats
- Most lipids stored in plants are oils
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9. Adenosine Triphosphate (ATP)
- Is the major energy-carrying molecule in a cell
- Energy from carbohydrates and lipids must be transferred to ATP to provide fuel for the cells
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10. Nucleic Acid
- Blueprints of Life
- Made up of nucleotides, that store information (recipe book)
- DNA is a nucleic acid… makes you different from the rest
Next - Cell Theory, Prokaryotic and Eukaryotic Cells