Cells and Cell Organelles Flashcards
What is the Cell Theory?
- All living things are composed of cells
- Cells are the simplest form of life
- All cells come from pre-existing cells (through mitosis of meiosis)
Cytosol/Cytoplasm
Jelly-like material inside a cell. Inside cytoplasm, it contains organelles such as the nucleus, ribosomes, vacuoles.
JOB: help dissolve solutions and move materials around the cell, facilitate chemical reactions, and add support to cell.
Nucleus
Directs the cell activities, as it contains almost all of the DNA of a cell and nucleoplasm. Chromozones are seen as chromatin. It is surrounded by a double membrane (nuclear envelople). The outer membrane continues onto the Endoplasmic Reticulum. The nucleolus (inside the nucleus) is responsible for making ribosomes. Inside has chromatin which holds info to make proteins
Endoplasmic Reticulum
Connected to the nuclear envelope. Allows genetic material to get to ribosomes so proteins can be made. There is a rough endoplasmic reticulum and a smooth endoplasmic reticulum
Rough Endoplasmic Reticulum
Contains ribosomes from the nucleus (mixture of proteins and RNA), so proteins are manufactured here and are then exported out of the cell. Is covered in ribsosomes.
Smooth Endoplasmic Reticulum
No ribosomes, where fat is synthesized and breakdown of carbohydrates and poisons/chemicals. Called smooth ER because it has no ribosomes
Ribosomes
Located on the rough endoplasmic reticulum. Composed of RNA. RNA (which has left the nucleus) gets read on ribosomes, which is how proteins are made in the body. Created by nucleolus. Transported by the rough endoplasmic reticulum.
JOB: make proteins
Vesicles
Term of any membrane bound or formed sac that stores and transports molecules
Vacuole
can be numerous and isolate/dispose of waste in the cell, or can be one large vesicle in plants that stores nutrients and water. Keeps the cell rigid, which allows the plant to stay upright on its own weight.
JOB: store food, water, waste.
In plant cells, it is often the largest part of the cell (called large central vacuole) because of its large size, it pushes the other part to the edges of the cell
In animal cells, they are small and scattered but serve same function
Golgi Body
Collect and process materials to be removed from the cell. The materials are dropped off by the vesicle. Put finishing touches on polypeptides, creating usable proteins for the body.
JOB: receives proteins that the ribosomes made, and modifies sorts, and packages proteins. Put proteins inside a vesicle when done
Lysosomes
sacs that pinch off the Golgi body apparatus containing digestive enzymes that break down larges molecules into smaller ones.
JOB: break down food, kill pathogens and destroy dying cells
Peroxisomes
similar to lysosomes, but enzymes in these break down toxic molecules mostly (many are in liver)
Mitochondria
Reactions resulting in cellular respiration occur, providing energy for the cell by breaking down organic molecules. Many folds on the organelle, so more of the energy reactions can occur. Make ATP, and contain their own DNA and membranes.
JOB: create ATP in a process called cellular respiration
Chloroplast (only in plant cells)
Contain the chemicals to perform photosynthesis, which takes CO2, sunlight, and water, and turns them into molecules that plants use as energy (glucose). Contain chlorophyll which helps trap sunlight specifically. Contain own DNA and ribosomes.
JOB: perform photosynthesis.
Cell Wall and ECM
The cell wall is usually composed of polysaccharides and glycoprotein; both rigid and porous, so it supports the plant while allowing materials through it. Cells can also be connected to other cells via junctions. The outermost layer of the plant. Humans don’t have cell walls, the Plasma membrane is protected by cell wall. Can last for years after the cell has died.
