Biology Life Functions and Cells

Life Functions

• Living organisms take in materials for growth and repair (Nutrition)
• Materials are distributed throughout the organism (Transport)
• Nutrients are broken down to make energy (Respiration)
• Cellular/metabolic waste is removed (Excretion)
• Organisms increase in size or cell number (Growth)
• Smaller molecules combine to create larger ones (Synthesis)
• Various activities are controlled and coordinated (Regulation)
• Offspring are produced (Reproduction); needed for species survival, not individual survival
• Chemical activities to maintain life (Metabolism)
• Maintaining a stable internal environment (Homeostasis)

Cells

• Levels of organization are Organelle, Cell, Tissue, Organ, Organ System, Organism
• Organelles are specialized structures inside cells that perform specific tasks
• Cells are the basic structural and functional units of life
• Tissues are groups of similar cells performing a specific function
• Organs are groups of tissues working together
• Organ systems are groups of organs working together
• An organism is made up of many organ systems

Parts of the Cell/Cell Organelles

• Cell membrane: A semi-permeable layer that controls material movement into and out of the cell
• Cell wall: Structural support for plant cells
• Cytoplasm: A gel-like substance that holds organelles in place
• Nucleus: Controls cell activities and contains genetic information
• Mitochondria: Produces energy through cellular respiration
• Ribosomes: Sites of protein synthesis
• Vacuoles: Store materials
• Chloroplasts: Sites of photosynthesis (plants only)

Plants

• Leaves have guard cells/stomates for gas exchange (CO2 in, O2 out), water movement, and maintenance of homeostasis under various conditions.
• Stomates open/close based on conditions like wet/dry or day/night.
• Photosynthesis occurs in chloroplasts in the leaf.
• Sunlight, water, and carbon dioxide are used to create glucose and oxygen.

Photosynthesis Equation

• 6CO2 + 6H2O + Light Energy → C6H12O6 + 6O2

Respiration

• Aerobic respiration: Oxygen is used to produce 36 ATP (energy), while anaerobic respiration produces less ATP without using oxygen.

• ATP- Adenosine Triphosphate, the energy currency of the cell obtained during respiration.

Energy Pyramid

• Producers (autotrophs)
• Primary consumers
• Secondary consumers
• 10% of energy transfers from one trophic level to the next, 90% is lost.
• Decomposers, herbivores, omnivores, and carnivores are part of food webs and food chains.

Biochemistry

• Energy is stored in chemical bonds.
• Organic molecules contain carbon and hydrogen
• Water does not contain carbon
• Macromolecule building blocks: amino acids (proteins), fatty acids and glycerol (lipids), simple sugars (carbohydrates) and nucleotides (nucleic acids).
• Proteins are made of amino acids.
• Lipids are composed of fatty acids and glycerol and are crucial for cell membranes.
• Carbohydrates (sugars, starch) are primarily made of glucose .
• Nucleic acids (DNA and RNA) are needed for genetic information.

Body Systems

• Nervous system: Sends messages
• Circulatory system: Transports materials
• Respiratory system: Gas exchange (takes in oxygen and removes carbon dioxide)
• Excretory system: Removes waste
• Digestive system: Breaks down food

Dehydration Synthesis

• Building larger molecules from smaller molecules, releases water as a byproduct.

Hydrolysis

• Breaking down large molecules into smaller ones by adding water as a reactant