Cell Theory
idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
Robert Hooke
Developed a simple lens microscope in 1665
Anton von Leeuwenhoek
Developed a compound microscope in 1674
Theodor Schwann
Worked with animal tissues
Matthias Schleiden
Worked with plant tissues
Cytology
The study of cells
Cytologist
A person who works with cells
Cell types
- Prokaryotic
- Eukaryotic
Prokaryotic Cells
These organisms would have evolved before a nucleus. The most abundant cell type.
Eukaryotic Cells
These organisms contain a nucleus.
Surface-to-Volume Ratio Importance
- A cell must be large enough to contain DNA, Ribosomes, and some cytoplasm
Three main parts to Eukaryotic Cells
- Cell membrane
- Nucleus
- Cytoplasm or cytosol
Nucleus
- Acts as a control center for all activities performed by the cell
- The source of genetic information (DNA)
Nuclear Envelope
- Protects DNA
- Made of a double membrane layer of Phospholipids
- Contains pores composed from proteins for molecules to travel through, such as nucleotides to make mRNA.
DNA
- Chromatin phase
- Chromosome phase
Chromatin phase
- A cell can move the DNA to find the gene of importance
- Loosely wrapped
Chromosome phase
- Used for separating the DNA equally during cell division
- Tightly wrapped
Nucleolus
- The site of RNA synthesis
- Responsible for helping to make Ribosomes
- Makes mRNA and other types of RNA molecules
Ribosomes
- Cellular particles made of rRNA and proteins
- The site of protein synthesis
- Free Ribosomes and Bound Ribosomes
Free Ribosomes
- Free floating ribosomes in the cytoplasm of a cell
- Found in all types of cells
Bound Ribosomes
- Attached to the Endoplasmic Reticulum
- Only found in Eukaryotes
- Makes proteins that will leave the cell to be used elsewhere
Endoplasmic Reticulum (ER)
- Composed of a network of small tubes called cisternae
- They are always found just outside and around the nucleus
- Smooth and Rough
Smooth Endoplasmic Reticulum (SER)
- Helps with the synthesis of lipids, phospholipids, and steroids
- Helps with carbohydrate breakdown
- Helps to detoxify blood
- Liver cells and muscle cells have lots of SER
Rough Endoplasmic Reticulum (RER)
- Helps with protein synthesis
- Bound to the outside of an organelle and deposits the protein inside as it is made by the ribosome
Golgi Apparatus
- Modifies proteins by attaching glycoproteins to them
- Composed of flattened tubes called cisternae
Lysosomes
- Involved in digestion and recycling of molecules
- Full of digestive enzymes (Lysozyme)
- Composed of a phospholipid bilayer
Vacuoles
Cell organelle that stores materials such as water, salts, proteins, and carbohydrates
Vesicles
Small membrane sacs that specialize in moving products into, out of, and within a cell
Endocytosis
The process of bringing something into the cell
Exocytosis
Process by which a cell releases large amounts of material
Phagocytosis
The process of cell "eating
Pinocytosis
The process of cell "drinking
Mitochondria
- The powerhouse of the cell
- Makes energy by performing cellular respiration
- Has it's own DNA, Ribosomes, and enzymes
Chloroplasts
- The site of photosynthesis
- Has it's own DNA, Ribosomes, and enzymes
Cytoskeleton
- Helps support and protect the cell
- Helps keep inner organelles organized
- Helps in cell motility or cell organelle movement
- Composed of various sized protein fibers
Microtubules
A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella.
Microfilaments
Fine, threadlike proteins found in the cell's cytoskeleton
Intermediate Filaments
Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments
Characteristics of living things
- Composed of cells
- Responds and adapts to the environment
- Uses energy
- Grows and reproduces