Chapter 3 Flashcards
The Cell
considered the basic unit of life
Cell Structure
Plasma, cytoplasm, and organelles
Plasma Membrane
Protects the inner contents of the cell, separates the water inside and outside, and controls what enters and leaves the cell
Organelles
Cytoskeleton
Ribosomes
Endoplasmic Reticulum (ER)
Golgi Apparatus
Mitochondria
Lysosomes
Cilia and Flagella
Nucleus
Cytoskeleton
These are a system of proteins that provide a framework for the inside of the cell
Ribosomes
Tiny granules that contain RNA and are involved in protein synthesis, including enzymes. Also the protein factory
Endoplasmic Reticulum (ER)
Is a system of membranous channels that extend through the cytoplasm of the cell - like a canal system.
Two Types:
Smooth ER
Rough ER
Smooth ER
no ribosomes; smooth appearance.
Rough ER
contains ribosomes - thus has a granular or “rough” appearance.
Golgi Apparatus
Consists of flattened sacs stacked on each other. It is a packaging center for the cell.
Mitochondria
Tiny, rod-shaped organelles. Referred to as the “powerhouses” of the cell because they produce ATP (energy) that keeps the cells alive and provides the “power” for cellular functions such as muscle contraction.
Production of ATP in the Mitochondria
Cellular respiration. Cellular respiration requires glucose (primarily), oxygen, and specific enzymes. Byproducts of the ATP production are carbon dioxide, water and heat.
Lysosomes
Are round packets of digestive enzymes which have been manufactured by the cell and packaged by the Golgi complex.
Cilia
are small, hairlike structures that move materials outside of the cell.
Flagella
Longer than cilia; usually 1 per cell. They are used for moving the cell
Nucleus
Large, usually round organelle; some cells have more than one while others do not have any. It is the control center of the cell.
Passive Transport
involve concentration gradients. No energy is used by the cell.
Diffusion
The movement of materials from an area of high concentration to an area of lower concentration until the material is evenly distributed. Very common method of moving materials into and out of the cell.
Osmosis
The movement of water from an area of high concentration to an area of low concentration through a cell membrane.
Filtration
The movement of solvents (such as water) and dissolved substances across a selectively permeable membrane due to pressure. Materials are forced thru due to the pressure
Active Transport
Not all movement of materials into and out of cells can be explained by concentration gradients.
Phagocytosis
Cell “eating.” Certain white blood cells can use phagocytosis to ingest bacteria or debris that may be harmful to the cell. Lysosomes usually dispose of the ingested substance.
Pinocytosis
Cell “drinking” Similar to phagocytosis except that the sac that is formed includes water as well as solutes (usually large) trapped in the water.
Mitosis
When cells are damaged, diseased, old, or reach a critical size, they undergo mitosis. This is also critical for growth of an individual.
Phases of Cell Division
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
Interphase
Is the period between cell divisions. During this phase, the DNA replicates but doesn’t appear as distinct strands yet. The indistinct DNA is known as chromatin.
Prophase
During prophase, the chromatin changes and becomes the now visible chromosomes.
Metaphase
During this phase, the chromatids line up in the middle of the cell.
Anaphase
In this stage, the duplicated chromosomes move away from the center to opposite sides of the cell. One of each pair moves to opposite sides so that there are identical chromosomes on each side.
Telophase
In telophase the chromosomes have reached the opposite sides and new membranes start to form around the chromosomes, creating two new nuclei each containing the same genetic material.
Cytokinesis
This is the actual division of the cytoplasm, which begins during late anaphase. A “pinching” of the cytoplasm occurs until it is completely cut through and thus forms two new, identical cells.
Protein Synthesis
The cell’s DNA (or the genes) code for all of the many proteins that make up our body and its parts.
Transcription
In transcription, the DNA molecule unwinds to expose a particular section of bases that is the code for a particular protein. It is then copied.
Translation
The mRNA leaves the nucleus and proceeds to attach to a ribosome. The ribosome “translates” or reads the code contained in the mRNA.
