diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index aab106c..d1b354f 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -70,15 +70,75 @@ A person contains roughly 100 trillion cells - All organelles are suspended in cytosol - Cytoplasm is the cytosol along with everything in a cell, excluding the nucleus -## Rough Endoplasmic reticulum -The endoplasmic reticulum is a network of tubules and flattened sacs with a "rough" appearance because of the presence of ribosomes on the surface +## Endoplasmic Reticulum +- Network of tubules and flattened sacs +- Transport proteins via cytoskeleton in vesicles -### Function -- Protein synthesis - - About half of the cell's proteins are made here, by the ribosomes -- Protein movement - - Proteins are transported by vesicles throught the cell to other organelles, like the golgi apparatus -- Protein "Proof-Reading" - - pre-existing proteins are center the rough-ER for modification +### Rough ER +- Appears "rough" due to the ribosomes attached to its outer surface +- Located directly adjacent and attached to nucleus +- Located next to Golgi apparatus +- Ribosomes in rough ER synthesize proteins + - Only specific proteins are synthesized by ribosomes of rough ER + - Proteins synthesized in ribosomes of rough ER are always sent to either Golgi apparatus via vesicles or stay in rough ER + - Ribosomes attach to and leave the rough ER regularly + - About half the cell's proteins are produced here +- Modify, fold, and fix proteins +### Smooth ER +- Does not synthesize proteins +- Appears "smooth" due to lack of ribosomes +- Located directly adjacent and attached to nucleus +- Synthesizes lipids (fats, e.g., cholesterol) +- Metabolises carbohydrates +## Lysosome + - Spherical vesicle that contains enzymes + - Digests and kills foreign matter which is then excreted + - Digests and breaks down old and unused material to be recycled + - Digests and breaks down old or non-functional organelles as needed + - Only plays a very minor role in cell suicide (apoptosis) + - If lysosome does rupture (accidentally) everything dies + +## Mitochondrion + - **Plural is "mitochondria"** + - Contains an inner and outer membrane + - Processes glucose + oxygen gas to form carbon dioxide + adenosine triphosphate (ATP) + - ATP allows proteins to do things (e.g., spend 1 ATP break 1 molecule) + - ATP cannot be stored + - Mitochondria have their own DNA + +## Cytoskeleton + - Made of protein filaments + - Maintains and changes cell structure, much like a human skeleton + muscular system + - Moves cells + - Chemicals can travel along cytoskeleton, e.g., organelles, vesicles, etc. + +## Organelles specific to animal cells +### Centrioles and centrosomes + - Made of same protein as cytoskeleton + - A centrosome is a pair of centrioles + - Very important to cell division + - Split chromosomes apart after DNA has been replicated into daughter cells + - Helps regulate cell division + - Create cilia and flagella (e.g., small hair-like things that swipe dirt out of lungs and tails of sperm, respectively) + +### Lysosomes + +## Organelles specific to plant cells +### Cell wall + - Provides structure and prevents cell rupture + - Can be tough, flexible, and/or rigid + - Permeable to small molecules + - Made of cellulose (type of sugar) + - Also present in most bacteria, fungi, and protists + +### Central vacuole + - Extremely large, may take up to 90% of volume in cell + - Contains water + - Maintains turgor pressure against cell wall (pushes against cell wall in all directions) + +### Chloroplasts + - Conduct photosynthesis + - All chlorophyll is located in chloroplasts + - Looks green \ No newline at end of file