Chapter 3:Cells Flashcards
Define cell nucleus
The nucleus house is genetic material that directs all cell activities. It is large roughly spherical structure enclosed by double layered nuclear envelope
What is a double membrane surrounding the cell nucleus, that separates the nucleus from the cytoplasm and also consists of inner and outer lipid bilayer membranes. Has protein lined channels called nuclear pores that allow certain molecules to exit the nucleus
Nuclear envelope
What is a complex opening formed with about 100 types of proteins that’s large enough to let out RNA molecules that carry genes messages not large enough to let out DNA itself must remain in nucleus
Nuclear pore
What is the structure near the Golgi apparatus and nucleus that is non-membranous and consists of two hollow cylinders called centrolies that lie at right angles to each other each centrioles are composed of nine groups of three microtubules
Centrosome
What is the function of a centrosome?
During mitosis they distribute chromosomes to new formic cells it is also a cellular organelle that separates the chromosomes into two cells from one during cell division.
Define centrioles:
Cellular structure built of microtubules that organizes mitotic spindle
What is the elongated fluid-filled sex of an organelle that are oblong and vary someone in size and shape it has an outer and inner layer the inner layer is folded extensively into portions these increase in surface area connected to Chris day our enzymes that control some of the chemical reactions
This is the mitochondria.
Mitochondrial DNA is?
Essential to the normal function of metabolic pathways in mitochondria.
What is the function of mitochondria?
Housing most of the biochemical reactions that extract energy from nutrients and digested food. They move slowly through the cytoplasm and reproduced by dividing. Enzymes connected to Chris day that controls some chemical reactions that release energy from nutrients and process called cellular respiration mitochondria store this energy otherwise known as ATP. A cell can easily use energy stored as ATP very active cells such as muscle cells have thousands of mitochondria mitochondria also contain a small amount of their own DNA.
What is an organelle of tiny membrania sacs they butt off sections of Golgi apparatus membranes?
This is a lysosome
Describe the function of a lysosome
They contain enzymes that break down worn out cell parts and debris. They maintain the acidic pH that enables enzymes to function and shield the rest of the cell from acidic conditions. Lysosomal enzymes break down nutrient molecules, or ingested materials. Lysosomes destroy one cellular parts, and digest certain white blood cells of bacteria an example of this is in liver cells lysosomes break down cholesterol toxins and drugs.
What is an exosome
Vessels that deliver proteins and lipids to other cells they remove debris transport immune system molecules, from cell to cell and provide vast communication Network among cells
What is a vesicles function
Store or transport substances within a seller between cells. Larger vesciles bring solid material from outside cells into cytoplasm. Smaller vesciles shuttle material from the rough endoplasmic reticulum to the Golgi apparatus as part of the secretion process.
Define Vesciles
Membraneous sacs. Larger vesciles that contain mostly water form when part of a cell membrane folds inward and pinches off
Define Golgi apparatus
Organelle that prepares and modifies proteins and glycoproteins for secretion. Stack of 5 to 8 flattened membranous sacs (resembles pancakes) a cell may have multiple Golgi apparatus enclosed and vesicles composed of membrane from the endoplasmic reticulum.
What is the movement into and out of the cell an example would be a transport vesicles may move to infuse with the cell membrane releasing its contents to the outside as a secretion
This is an example of exocytosis
What is the function of Golgi apparatus?
Refines, packages, and transports protein synthesized by ribosomes associated with the endoplasmic reticulum. Proteins arrive at Golgi apparatus enclosd in vesciles composed of membrane from the endoplasmic reticulum. Sugar molecules attached to some proteins in endoplasmic reticulum are called glycoproteins these vesciles fuse with the membrane and at innermost end of Golgi apparatus these are specialized to receive glycoproteins as they pass from layer to layer through the Golgi stacks they are modified chemically. Some sugars may be added or removed and proteins short and when they reach the outermost layer they are packaged in bits of Golgi membrane, which but off to form transport vesciles.
Define the nucleus
The word means “little nucleolus”it’s a small dense body composed of largely RNA and protein has no surrounding membrane and forms a specialized region of certain chromosomes together. Ribosomes form here and then they migrate through nuclear pores to the cytoplasm
What consists of loosely coiled fibers of DNA and protein, condensed to form chromosomes during mitosis, when cell begins to divide they coil tightly and then they condense to form individual chromosomes. At times the chromatin unwind to permit access to information in certain genes
Chromatin.
What are some passive mechanisms that do not require cellular energy?
Diffusion, facilitated diffusion, osmosis and infiltration
Describe the function of the endoplasmic reticulum.
The membraneous parts interconnected and communicate with the cell membrane, the nuclear envelope, and other organelles. It also provides a vast tubular Network to transport molecules from a cell part to another the endoplasmic reticulum participates in synthesis of protein and lipid molecules. These molecules may leave the cell as secretion or used within the cell for functions like producing new endoplasmic reticulum or cell membrane as the cell grows. It also acts as a quality control center for the cell. It’s chemical environment enables a forming protein to start to fold into the shape necessary for its function, can I identify and dismantle a misfolded protein. Proteins being synthesized move through the endoplasmic reticulum tubules to another organelle called the Golgi apparatus.
This is the contents of the cell, including the gel-like cytosol and organelles except the nucleus this is enclosed by the cell membrane within the cytoplasm the organelle are structure and cell with special functions. This is not static or still they either are moving inside the cell or partake in ongoing biochemical activity.
This is what we call a cytoplasm
Please define organelle
These perform a specific function, portion of biochemicals that might harm other cell parts. They dismantled debris, process secretions, and extract energy from nutrients, they also interact with each other creating vast networks throughout the cell and they also conduct activities such as food breakdown, producing energy, heat and protein lipid production / packaging and they also maintain the cell shape.
Describe in depth about the cell membrane
It’s an actively functioning part of living material that also regulates substances in and out of the cell and is the site of a lot of biological activity it also helps attach to certain other cells and helps form tissue.
