From ee001a039c144666184398258431d18df77eba4c Mon Sep 17 00:00:00 2001 From: James Su Date: Mon, 28 Oct 2019 01:02:20 +0000 Subject: [PATCH] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 149 +++++++++++++++++---- 1 file changed, 125 insertions(+), 24 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index 2dad150..ad5ecee 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -40,22 +40,22 @@ A person contains roughly 100 trillion cells ### Cell Membrane - - Controls what substances enter/leave the cell selectively via various receptors/osmosis +- Controls what substances enter/leave the cell selectively via various receptors/osmosis - Allows nutrients to enter - Allows waste products to leave - - Surrounds and holds other organelles in cell - - Interact with outside chemicals (e.g., hormones) +- Surrounds and holds other organelles in cell +- Interact with outside chemicals (e.g., hormones) ### Nucleus - - Holds deoxyribonucleic acid (DNA) in form of chromatin +- Holds deoxyribonucleic acid (DNA) in form of `chromatin` - DNA is a double helix that make genes - - Genes are a complete set of instructions to make a complete product (typically proteins) + - `Genes` are a complete set of instructions to make a complete product (typically proteins) - `Genes`: one of the many sets of instructions, in your DNA, found on a **chromosome**, for making a functional product (mostly proteins) - - Chromatin is DNA wrapped tightly in protein - - Chromosomes are even more tightly wrapped chromatin used in cell division only - - Surrounded by a double membrane - - Substances enter and exit the nucleus via nuclear pores - - Messenger RNA (mRNA) is encoded from DNA and sent to ribosomes to produce proteins + - `Chromatin` is DNA wrapped tightly in protein +- `Chromosomes` are even more tightly wrapped chromatin used in cell division only +- Surrounded by a double membrane +- Substances enter and exit the nucleus via nuclear pores +- Messenger RNA (mRNA) is encoded from DNA and sent to `ribosomes` to produce proteins ### Nucleolus @@ -65,24 +65,125 @@ A person contains roughly 100 trillion cells - Is *not* surrounded by a membrane, literally is just same as rest of nucleus but denser ### Cytoplasm & Cytosol - - Cytosol is the fluid cells contain - - All organelles are suspended in cytosol - - Cytoplasm is the cytosol along with everything in a cell, excluding the nucleus + - `Cytosol` is the fluid cells contain + - **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 +- The endoplasmic reticulum is a network of tubules and flattened sacs with a "rough" appearance because of the presence of `ribosomes` on the surface +- 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 can enter the rough-ER for modification +## Rouch Endoplasmic Reticulum +- 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** + +### Functions +- **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 can enter the `rough-ER` for **modification** + +## 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 ## Golgi Apparatus (Golgi Complex) -- Receives, modifies and transports proteins that were produced by the rough-E.R -- Packages proteins into vesicles and sends them cell membrane for export +- **Receives, modifies and transports** proteins that were produced by the `rough-E.R` +- **Packages** proteins into `vesicles` and sends them `cell membrane` for export + +## Lysosome +- `White blood` cell uses the cytoskeleton to reach out and swallow up a bacterium, then uses `lysosomes` to break it down +- 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 + +### Functions +- **Digestion** + - Food or foriegn matter (invaders) are swallowed up and executed +- **Recycling** + - When an organelle "dies" `lysosomes` will recycle the dea material back into raw materials cellular suicide +- **Cellular suicicde** + - This is not good for the cell (obviously, but it is good for us. (E.g reasons why most of us don't have web feet/hands) + +## Midtochondria + - **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 +- The cytosekleton **is** the skeleton of the cell, found in the `cytosol`, made up of protein. +- The cytoskeleton is also like the muscular system, able to change teh sahpe of cells in a flash +- 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 +1. centrioles and centrosomes +2. lysosomes + +### Centrioles and Centrosomes +- Involved in the process of cell division for animal cells, plant cells **DO NOT** use centrioles + - 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 +- Present in all animal cells but not present in the cells of most plants + +## Organelles Specific To Plant Cells +1. Cell wall +2. Chloroplast +3. Central Vacuole + +### 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 + +### Chloroplast +- The `solar panel` of the plant cell. +- Conducts photosynthesis +- All chlorophyll is located in chloroplasts +- Looks green + +### 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) +- **Provides the cell with shape** + + + + + + + +