From 519a2a9d4a9f121b06c3dc2a21c175580339f23e Mon Sep 17 00:00:00 2001 From: James Su Date: Thu, 7 Nov 2019 02:21:01 +0000 Subject: [PATCH] fixing some many mistakes left by eggy, and making things clear, more detailed, and more in-depth. --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 127 +++++++++++++-------- 1 file changed, 78 insertions(+), 49 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index 8fecdb2..e6a1acf 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -40,28 +40,30 @@ A person contains roughly 100 trillion cells ### Cell Membrane -- Controls what substances enter/leave the cell selectively via various receptors/osmosis - - Allows nutrients to enter - - Allows waste products to leave +- Controls what substances **enter/leave** the cell selectively via various receptors/osmosis + - Allows **nutrients** to enter + - Allows **waste products** to leave (removal of waste) - Surrounds and holds other organelles in cell - Interact with outside chemicals (e.g., hormones) +- Must transport food (ATP), nutrients into the cell ### Nucleus +- Is the control center of the cell - Holds deoxyribonucleic acid (DNA) in form of `chromatin` - DNA is a double helix containing genes - - `Genes` are a full set of instructions in DNA to make either RNA or a protein - - `Chromatin` is DNA wrapped tightly in protein -- `Chromosomes` are even more tightly wrapped chromatin used in cell division only + - `Genes` are a full set of instructions in DNA to make either RNA or a protein, they are **found** in the DNA + - `Chromatin`: is DNA **wrapped tightly** in protein +- `Chromosomes`: are even more tightly wrapped `chromatin` used in cell division only, formed when `DNA` **condenses** in `mitosis` - Surrounded by a double membrane -- Substances enter and exit the nucleus via nuclear pores +- Substances enter and exit the nucleus via `nuclear pores`. `Nuclear pores` are holes in the membrane that allow `proteins` and `nucleic acids` into the `cytoplasm` - Messenger RNA (mRNA) is encoded from DNA and sent to `ribosomes` to produce proteins -- Humans have ~2 m of genes per cell per nucleus tightly wrapped +- Humans have ~2 meters of genes per cell per nucleus tightly wrapped ### Nucleolus - - Dense region of DNA located in the nucleus + - Dense region of DNA located in the nucleus (codes `ribosomes`; enzyemes that make protein) - This area of DNA is specially for ribosomal DNA (rDNA), or DNA used to make ribosomes - - Produce "large" and "small" subunits of ribosomes, which either form complete ribosomes in cytosol or mix with endoplasmic reticulum, forming rough endoplasmic reticulum (RER) + - Produce "large" and "small" subunits of `ribosomes`, which either form complete `ribosomes` in `cytosol` or mix with `endoplasmic reticulum`, forming `rough endoplasmic reticulum` (RER) ### Cytoplasm & Cytosol - `Cytosol` is the fluid cells contain @@ -69,7 +71,7 @@ A person contains roughly 100 trillion cells - `Cytoplasm` is the `cytosol` along with everything in a cell, excluding the nucleus ## 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 +- 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 - **Transports** proteins via cytoskeleton in vesicles @@ -83,11 +85,11 @@ A person contains roughly 100 trillion cells - Folds, fixes and **modifies both newly-created and pre-existing proteins** somewhat like **proof-reading** ## Specific to Smooth ER -- Does not synthesize proteins +- **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 +- **Metabolises** carbohydrates ## Golgi Apparatus - Also known as Golgi body, Golgi complex, etc. @@ -107,73 +109,100 @@ A person contains roughly 100 trillion cells - 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 + - ATP is needed for daily function of the cell ## Cytoskeleton -- Made of protein filaments -- Maintains and changes cell structure, much like a human skeleton + muscular system +- Made of **protein filaments** +- **Maintains** and **changes** cell structure, much like a human skeleton + muscular system - Moves cells - Modifies and adjusts cell structure as needed -- Chemicals can travel along cytoskeleton, e.g., organelles, vesicles, etc. +- Chemicals can travel along `cytoskeleton`, e.g., `organelles`, `vesicles`, etc. ## Organelles specific to animal cells +1. Centrioles and centrosomes +2. Lysosomes ### Centrioles and centrosomes - - Made of same protein as cytoskeleton - - A centrosome is a pair of centrioles + - Made of same protein as `cytoskeleton` - Important to cell division in animal cells - Create cilia and flagella (e.g., small hair-like things that swipe dirt out of lungs and tails of sperm, respectively) ### Lysosomes +- Explained before. ## 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 -- Made of cellulose (type of sugar) +- Provides **structure** and prevents **cell rupture** +- A more stronger, thicker, rigit version of the `cell membrane` +- Made of **cellulose** (type of sugar) - Also present in most bacteria, fungi, and protists +- The antibotic **Penicillin** works by destroying the cell walls of bacteria, thereby killing the bateria ### Chloroplast -- The `solar panel` of the plant cell -- Conducts photosynthesis +- The **solar panel** of the plant cell +- Conducts **photosynthesis** - All chlorophyll is located in chloroplasts - Looks green +- Parts of the plant that do not photosynthesize do not have chloroplasts ### 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) - Maintains cell shape and resistance - - Plant cells that lack turgor pressure (e.g., celery left in fridge) become flaccid + - Plant cells that lack **turgor pressure** (e.g., celery left in fridge) become **flaccid** -## Cell division -### Purpose -#### Growth - - Cells have maximum size before transportation of substances within cell becomes inefficient - - Cells transport chemicals (e.g., nutrients) via `diffusion` +## Cell Division -#### Reproduction - - Single-cellular organisms reproduce via division asexually +## Purpose + +### 1. Reproduction + - Single-cellular organisms reproduce via division **asexually** - Multicellular organisms reproduce via combining two germ cells ("sex cells") that contain half the DNA each of two organisms - - This is sexual + - This is **sexual** -#### Repair - - Cells naturally die and need to be replaced - - e.g., red blood cells, hair cells, skin, injuries +### 2. Growth + - Cells have maximum size before transportation of substances within cell becomes **inefficient**, due to **larger cells** decreasing efficiency of `diffusion` + - Cells transport chemicals (e.g., nutrients) via `diffusion`, this **limits cell size** + - The only way to maintain proper function and get bigger is to **add more cells** -### Cell cycle - - Interphase - - G1 - - S - - G2 - - Mitosis + +### 3. Repair +- **Organisms need to repair cells to stay alive and maintain proper health** +- Millions of cells are replaced everyday +- Cells naturally die and need to be replaced + - e.g., red blood cells, hair cells, skin, injuries, broken bones + +## Cell cycle +- **Interphase** + - **G1** (normal groth and function), + - Prepare for cell divison + - Duplication of DNA **S**, + - Duplication of organelles **G2** +- **Mitosis** - Occurs only in eukaryotic cells - - Prophase - - Prometaphase - - Metaphase - - Anaphase - - Telophase - - Cytokinesis - - G0 + - P-MAT: Prophase Prometaphase, Metaphase, Anaphase, Telophase Cytokinesis + - nuclear divison +- **Cytokinesis** + - **cell division** +- **G0** - Cell no longer divides - - Outisde of cell cycle \ No newline at end of file + - Outisde of cell cycle + +### Mitosis +- PMAT (prophase, metaphase, anaphase, telophase) + + +## Cell Specialization +- `Zygote`: A one-celled organism formed from the fertilization of an egg by a sperm cell +- A cell's position in the `gastrula` (outer, middle, inner layer) will determine the fate of the cell, or its potiental. +- (LOCATION LOCATION LOCAION!) + +### Stem Cells +- They are an **unspecialized** cell that has the potential to become one of several types of cells. +- After cell division, either both can become stem cells or one stays as a stem cell and the other becomes a specialized cell +- \ No newline at end of file