Animal & Plant Cell Review © The Seismic Scientist

5.1 Matter & Energy Pathways in Living Systems 5.2 Photosynthesis Stores Energy in Organic Compounds 5.3 Cellular Respiration Releases Energy from Organic Compounds © The Seismic Scientist

Ch. 5 Photosynthesis & Cellular Respiration In this unit, you will: Relate photosynthesis to the storage of energy in organic compounds Explain the role of cellular respiration in releasing potential energy from organic compounds © The Seismic Scientist

Plant and Animal Cells Plants, animal, fungi & protists are made up of eukaryotic cells Eukaryotic cells have a nucleus Cells that make up animals have some structures that distinguish them from plant cells Plant cells have a cell wall Plant & animal cells have organelles Plant cells are larger than animals cells Plant cells have chloroplasts © The Seismic Scientist

Plant Cells © The Seismic Scientist

Animal Cells © The Seismic Scientist

Organelles © The Seismic Scientist

The Cell Membrane The cell membrane is a boundary that separates the internal environment of a cell from its external environment Composed of: Double layer of phospholipid molecules Structure: Head region: dissolves easily in water Tail region: insoluble in water Arranged into two, sandwich-like layers © The Seismic Scientist

Cell Membrane Peripheral protein Integral proteins Cholesterol Part of phospholipids attracted to water Part of phospholipids repelled by water Glyco-protein © The Seismic Scientist

Passive Transport: Diffusion The cell membrane is selectively permeable Allows some molecules to pass through it while preventing others from doing so Small molecules and ions move through the cell membrane by diffusion Diffusion is the natural movement of molecules or ions from a region where they are more concentrated to one where they are less concentrated Does not require energy from the cell © The Seismic Scientist

Diffusion © The Seismic Scientist

Diffusion © The Seismic Scientist

Movement of Substances The natural tendency of a substance to move from an area of high concentration to an area of lower concentration is often described as “moving down” or “following” its concentration gradient Differences in some quality between two adjacent regions Examples: concentration in pressure, electrical energy, pH © The Seismic Scientist

Concentration Gradients Low Concentration High Concentration Equilibrium © The Seismic Scientist

Cell and Membrane Water inside of the cell is referred to as intracellular fluid Water outside of the cell is referred to as extracellular fluid Cellular fluid diffuses freely through the cell membrane © The Seismic Scientist

Passive Transport: Osmosis The diffusion of a solvent across a semi-permeable membrane that separates two solutions is called osmosis Does not require energy from the cell © The Seismic Scientist

Osmotic Movement If the water concentration inside of the cells equals the water concentration outside of the cell, equal amounts of water move in and out of the cell at the same rate (cell is isotonic) If the water concentration outside the cell is greater than than the water concentration inside of the cell, water moves into the cell (cell is hypotonic) If the water concentration inside the cell is greater than the water concentration outside of the cell, then water moves out of the cell (cell is hypertonic) © The Seismic Scientist

Osmotic Movement Isotonic Solution Hypertonic solution Hypotonic solution Water moves in and out of the cell equally. Cell remains the same size. Water moves out of the cell. Cell shrinks in size. Water moves into the cell. Cell increases in size and bursts. © The Seismic Scientist

Facilitated Diffusion Some substances require assistance from the cell to diffuse across cell membranes Some cells are too big (ex. Glucose) Transport proteins recognize and move only one type of dissolved molecule or ion (based on shape, size and electrical charge) Carrier proteins helps the movement of glucose across a concentration gradient Specific shape Channel proteins transport charged particles across a membrane Tunnel shape No energy from the cell is required © The Seismic Scientist

Facilitated Diffusion © The Seismic Scientist

Active Transport Active transport uses energy to enable a cell to take in a substance that is more concentrated inside the cell than outside the cell Energy for active transport comes from a molecule called adenosine triphosphate (ATP) When one of three phosphates is split from ATP in a chemical reaction, energy is released that is harnessed to power a cellular function Also known as the sodium-potassium pump © The Seismic Scientist

Active Transport © The Seismic Scientist

Endocytosis Some cells use a specialized method to move substance across a cell membrane When the cell membrane folds inwards, creating a bubble-like sac called a vesicle, trapping and enclosing a small amount of matter from outside the cell is called endocytosis Three forms: Pinocytosis Phagocytosis Receptor-assisted endocytosis © The Seismic Scientist

Endocytosis Pinocytosis: the intake of a small droplet of extracellular fluid along with any dissolved substances or tiny particles that it may contain Phagocytosis: the intake of a large droplet of extracellular fluid, often including bacteria or bits of organic matter Receptor-assisted endocytosis: the intake of specific molecules that attach to special proteins in the cell membrane © The Seismic Scientist

Endocytosis © The Seismic Scientist

Exocytosis The removal of substances from the cell Steps: A vesicle from inside the cell moves to the cell surface Vesicle membrane fuses with the cell membrane Contents of the outward-bound vesicle are secreted into the extracellular fluid Important in the secretion of hormones © The Seismic Scientist

Exocytosis © The Seismic Scientist

Cell Transport Summary © The Seismic Scientist

Video Video – Membranes & Transport Crash Course © The Seismic Scientist