Cytoplasm – The clean gelatinous (jelly) fluid inside the cell. - Chemical reactions take place here. • Cells have an internal structure. Note: Cytoplasm is present in both prokaryotic and eukaryotic cells.
Cells have an internal structure. • The cytoskeleton has many functions. • supports and shapes cell • helps position and transport organelles • provides strength • assists in cell division • aids in cell movement cytoskeleton Infer: What problems might a cell experience if it had no cytoskeleton? cytoskeleton
Several organelles are involved in making and processing proteins. • The nucleus stores and protects genetic information (DNA).
Chromatin – granular material within nucleus – DNA bound to protein - Condenses to form chromosome at the time of cell division • Cells have an internal structure.
Several organelles are involved in making and processing proteins. • Many processes occur in the endoplasmic reticulum. • The endoplasmic reticulum aids in the production of proteins and lipids.
Several organelles are involved in making and processing proteins. • Making proteins and lipids occur in the endoplasmic reticulum. • There are two types of endoplasmic reticulum. Rough endoplasmic reticulum (ER) Smooth endoplasmic reticulum (ER)
The Golgi apparatus modifies, packages, and transports proteins for use within the cell and to be exported to other parts of an organisms • Several organelles are involved in making and processing proteins. Vesicle Golgi apparatus
Several organelles are involved in making and processing proteins. • Ribosomes are the place where amino acids bond to form polypeptide chains that will become proteins. There are 2 types of ribosomes: free floating and attached to the ER. Figure: Ribosomes attached to the ER.
Several organelles are involved in making and processing proteins. • Vesicles are membrane-bound sacs that isolate and transport materials within the cell and out of the cell.
Other organelles have various functions. • Mitochondria supply energy to the cell by making ATP.
Other organelles have various functions. • Vacuoles are fluid-filled sacs that hold materials like nutrients and wastes. • Plants have a large central vacuole that gives a plant structural support and is used for storing water and other substances. Note: A plant will wilt, its leaves shrivel because there is not enough water in each cell’s central vacuole to keep the plant upright.
Other organelles have various functions. • Lysosomes contain enzymes used to digest and recycle foreign materials or worn out parts. The optimum pH for a lysosome is about 5. The pH of the cytoplasm is about 7. Infer: How does this difference in pH offer some protection to the cell if a lysosome should leak? Example: In a liver cell, a mitochondrion has an average lifespan of 10 days. A lysosome engulfs the organelle, breaks it down and then releases the recycled material into the cytoplasm, providing raw material for the manufacture of more organelles.
Other organelles have various functions. • Centrioles are tubes found in the centrosomes. They are found in animal cells only. • Centrioles help divide DNA during cell division. • Centrioles also form cilia and flagella.
Cilia/Flagella – Short/long projections of microtubules. - aid in cell movement or help sweep liquids across the cell surface • Cells have an internal structure.
Plant cells have cell walls and chloroplasts. • A cell wall provides rigid support, protections and shape for plants, algae, fungi and most bacteria. • Animal cells do not have a cell wall present. NOTE: Cell wall composition varies: plants and algae have cell wall composed of cellulose. In fungi the cell was is composed of chitin and some bacteria have cell walls composed of peptidoglycan.
Plant cells have cell walls and chloroplasts. • Chloroplasts are organelles that convert solar energy to chemical energy (glucose) during the process of photosynthesis. Chloroplasts are located in plant cells, some algae and few bacteria. Analyze: Would it be accurate to say that a chloroplast makes energy for a plant cell? Explain your answer.