Biology; Cellular Biology Flashcards
5 Components of the Cell Theory
- All living things are composed of cells
- The cell is the basic functional unit of life
- The chemical reactions of life take place inside the cell
- Cells arise only from pre-existing cells
- Cells carry genetic information in the form of DNA, this genetic material is passed from parent cell to daughter cell
6 Kingdoms of Cell Structure
- Bacteria
- Archaea
- Protista
- Fungi
- Plantae
- Animalia
What are the 2 Major Types of Cells and Their Traits
Eukaryotic - Membrane-bound organelles.
Prokaryotic - Do not contain a nuclei or membrane-bound organelles, and only possess a cell membrane, cytoplasm, genetic material and ribosomes.
Fluid Mosaic Model
Phospholipid bilayer with cholesterol and embedded proteins.
Hydrophilic Exterior (Heads), phosphoric-acid region.
Hydrophobic Interior (Tails), fatty-acid region.
Cell Membrane
Regulates the passage of materials into and out of the cell. Small charged particles are usually able to cross the membrane through protein channels, well charged ions and larger charged molecules cross the membrane with the assistance of carrier proteins.
Ribosomes Function in Prokaryotes
Due to the lack of membrane-bound organelles both rRNA synthesis and ribosome function occurs in the cytoplasm.
What is the Difference Between a Rough ER and a Smooth ER
A rough ER contains ribosomes and contains a role in protein production, as smooth ER does not contain ribosomes and is involved with metabolism and the production of lipids.
Endoplasmic Reticulum (ER)
A network of membrane-enclosed spaces involved in the transport of materials throughout the cell, particularly those materials destined to be secreted by the cell.
Ribosomes
Facilitate protein production and are made up of 2 rRNA sequences called ribosomal subunits, rRNA molecules are synthesized in the nucleolus of eukaryotes.
Where do Ribosomes Function
They function either in the cytoplasm as unbound ribosomes or on the outer membrane of the rough ER as bound ribosomes.
Cytosol
The cellular fluid contained within the cell membrane.
Cyclosis
Streaming movement within the cell.
Cytoplasm
Most of the cell’s metabolic activity occurs in the cytoplasm, which includes the cytosol, transport within the cytoplasm occurs by cyclosis.
Golgi Apparatus
Primary site for cellular trafficking, receives vesicles and their contents from the smooth ER then modifies them, repackages them into vesicles and distributes them to the cell surface for exocytosis.
Exocytosis
Fusion of secretory vesicles with the plasma membrane and results in the discharge of vesicle content into the extracellular space and the incorporation of new proteins and lipids into the plasma membrane.
Nucleus
Contains DNA wound around structural proteins called histones, DNA can tighten or loosen its complexing with the histones. Contains nucleolus where ribosomal RNA (rRNA) synthesis occurs.
Histones
Histones are basic proteins, and their positive charges allow them to associate with DNA, which is negatively charged. Some histones function as spools for the thread-like DNA to wrap around.
What Happens to DNA During Replication
DNA tightly winds around the histones, compacting chromatin (loose DNA) into chromosomes.
What Happens to DNA During Transcription
DNA unwinds itself from the histones, allowing transcription to occur.
Prokaryotes DNA Structure
Prokaryotes don’t have a nuclei and therefore do not possess histones to organize DNA structure, DNA is then organized into circular chromosomes located in the nucleoid.
Vacuoles/ Vesicles
Membrane-bound sacs involved in the transport and storage of materials that are ingested, secreted, processed, or digested by the cell, vacuoles are bigger than vesicles
Centrioles
Composed of microtubules and are involved in spindle organization during cell division. Not bound by a membrane.
Lysosomes
Membrane-bound vesicles that contain hydrolytic enzymes involved in intracellular digestion, and break down material ingested by the cell.
Autolysis
The enzymatic digestion of cells by the action of its own enzymes, and it mostly occurs in dying or dead cells.
Cytoskeleton
Supports the cell, maintains its shape, and aids in cell motility. Composed of Microtubules, Microfilaments, and Intermediate Filaments.
