A2.2 Eukaryote Cell Structure Flashcards
Eukaryote cells are _____________________.
Organisms that contain a membrane-bound nucleus and organelles.
List the common organelles found in eukaryotic cells.
- Cell Membrane
- Endoplasmic Reticulum
- Ribosomes
- Golgi Apparatus
- Lysosomes
- Mitochondria
- Nucleus
- Chloroplasts (only in plant and algae cells)
- Centrosomes
- Vacuoles
Cell Membrane: Description/Composition
The cell membrane is composed of two layers of lipid molecules (phospholipids) with proteins that can be found on both sides, or through the membrane.
Cell Membrane: Function
Involved in:
* Import and export of small molecules and ions.
* Cell communication (proteins in the membrane act as receptors to chemical signals and allows the cell to respond appropriately).
* Cell growth, by adding a new membrane.
* Motility, by changing shape.
Chainsaw Man = Cell Membrane
ICCM = I C Chainsaw Man
Cell Membrane: Location
The cell membrane is located in the outermost layer of the cell (in animal cells).
Cytoplasm: Description/Composition
The cytoplasm is where all organelles are found. The fluid portion of the cytoplasm around the organelles is called cytosol.
Cytoplasm: Location
The cytoplasm occurs inside the plasma membrane.
Cytosol: Function
In the cytosol:
* Protein filaments form the cytoskeleton, which gives the cell its shape and provide basis for its movements.
Cilia: Description/Composition
Cilia are tiny-hair like appendages with a bundle of microtubules at their core.
Cilia: Location
Cilia extend from the surface in large numbers on many kinds of cells.
Cilia: Function
In Protozoa:
* Locomotion and to collect food particles.
Epithelial Cells (lining the human respiratory tract):
* Sweep layers of mucus, trapped particles of dust and dead cells to the mouth, to be swallowed.
Flagella: Description/Composition
Flagella are similar in structure to cilia, but much longer and typically thicker. Limited to one or a few per cell.
Flagella: Location
Flagella are anchored in the plasma membrane.
Flagella: Function
Function:
* Propagate waves along their length, which is used to propel a cell in a particular direction.
Microvilli: Description/Composition
Microvilli are microscopic appendages created by folds on the cell membrane. They contain actin filaments.
Micheal Afton = M in Microvilli + Actin Filaments
Microvilli: Location
Microvilli are found on epithelial cells lining the small intestine—on only one side of the cell.
Microvilli: Function
Function:
* Increase the surface area over which intestinal epithelial cells can absorb nutrients.
Rough Endoplasmic Reticulum: Description/Composition
The rough ER has ribosomes on the exterior of the channels.
Rough Endoplasmic Reticulum: Location
The rough ER tends to be closer to the nucleus.
Rough Endoplasmic Reticulum: Function
Function:
* As proteins are produced, they collect in the spaces between the membranes called cisternae. From inside the rER, proteins can be transported in vesicles to other parts of the cell such as the Golgi apparatus.
Smooth Endoplasmic Reticulum: Description/Composition
The smooth ER does not have ribosomes on the exterior of the channels.
Smooth Endoplasmic Reticulum: Function
Function:
* Produces phospholipids for the construction of membranes and lipids.
80S Ribosomes: Description/Composition
Ribosomes are composed of RNA and protein. In eukaryotic cells, ribosomes are larger and denser than those in prokaryotic cells.
80S Ribosomes: Location
Ribosomes may be found free in the cytoplasm or may be attached to the surface of the endoplasmic reticulum.
80S Ribosomes: Function
Function:
* Carry out protein synthesis in the cell.
Golgi Apparatus: Description/Composition
The Golgi apparatus consists of flattened sacs called cisternae, which are stacked one on top of another. It has a distinct structural directionality.
Gojo—Stacking and flipping ‘em; Pancakes = CISTERNAE
Golgi Apparatus: Process
- The Golgi apparatus receives products from the rER (cis side).
- Products are moved into the cisternae.
- Products are modified by adding carbohydrate or lipid components.
- The modified products are released in vesicles (trans side).
- Then are transported to the plasma membrane for secretion or other parts of the cell.
Gojo and Rika Delivery Service
Golgi Apparatus: Function
Function:
* Collection, packaging, modification and distribution of materials for secretion or delivery to other organelles.
Delivery Process (CPMD)
Endoplasmic Reticulum: Description/Composition
The ER is an extensive network of tubules or channels of membrane. It exists in two types: Smooth ER and Rough ER.
Endoplasmic Reticulum: Location
The ER extends from the nucleus.
Endoplasmic Reticulum: Function
Involved in:
* Transportation of materials (such as proteins and lipids) throughout the internal region of the cell.
List the main filaments.
- Actin filaments
- Microtubules
- Intermediate filaments
AMI
Lysosomes: Description/Composition
Lysosomes are sac bound by a single membrane that contains enzymes for breaking down proteins, lipids, carbohydrates, and nucleic acids.
lySOSoMEs: Sac bOund by a Single Membrane that contains Enzymes.
Lysosomes: Function
Function:
* Fuse with materials brought into the cell to break them down.
* Can also fuse with old or damaged organelles to recycle the various parts.
Fy-So-Somes; F = Fuse
Mitochondria: Description/Composition
Mitochondria are rod-shaped organelles that are similar in size to bacteria. Mitochondria have their own circular DNA and a double membrane. The outer membrane is smooth, while the inner membrane is folded into cristae.
GENERAL Mitochondria
M1 is smooth.
M2 is folded into cristae.
Mitochondria: Function
Function:
* The cristae provide a large surface area for the chemical reactions that produce adenosine triphosphate (ATP).
Cristae = Battlefield; ATP = Nuclear Weapon
Nucleus: Description/Composition
The nucleus separates the chromosomal DNA from the cytoplasm by an envelope consisting of a double membrane with pores. The nucleolus is a darkly stained area of the nucleus (where protein synthesis occurs).
Nucleus: Location
The nucleus is usually in the middle of the cell.
Nucleus: Function
Function:
* Nuclear pores allow material to move in and out of the nucleus.
* Site of DNA duplication and transcription of mRNA.
* Ribosome synthesis occurs in the nucleolus.
Chloroplasts: Description/Composition
Chloroplasts are surrounded by a double membrane (both are a continuous layer) and are about the same size as a bacterial cell. They contain their own circular DNA and 70S ribosomes.
Chloroplasts: Location
Chloroplasts are found only in algae and plant cells.
Chloroplasts: Function
Function:
* Site of photosynthesis.
Centrosomes: Description/Composition
Centrosomes consist of a pair of centrioles at right angles to one another. They duplicate during cell division.
Centrosomes: Location
Centrosomes are located at one end of the cell close to the nucleus.
Centrosomes: Function
Involved in:
* The assembly of microtubules (involved with cell movement and cell division).
Vacuoles: Description/Composition
Vacuoles occupy a very large space in plant cells.
Vacuoles: Function
Function:
* Stores organelles that are usually formed from the Golgi apparatus.
* Enables cells to have a higher surface area to volume ratio at larger sizes.
* May store a number of different substances, including potential food, metabolic waste, toxins, and water.
* In plants, vacuoles allow the uptake of water and exerts pressure on the cell wall, which provides rigidity.
Cell Wall: Description/Composition
In plants, the cell wall is made up of cellulose polymers wound together. In fungi, it is composed of chitin.
Cell Wall: Location
The cell wall surrounds the cell.
Cell Wall: Function
Function:
* Provides protection.
* Maintains the cell shape.
* Prevents excessive uptake of water.
* Helps hold up the plant against the force of gravity.
What are thylakoids?
Thylakoids are arranged in flattened circular piles called grana, which contains the pigments needed for photosynthesis. The thylakoid lumens are connected, which creates the thylakoid space. The fluid found between the grana is called the stroma.
What are plastids?
Chloroplasts belong to a family of organelles called plastids. Plastids are double membrane organelles which are responsible for manufacturing food and storing it.
List the types of plastids.
- Amyloplast: Accumulates and stores starch.
- Etioplast: Produces and stores lipids.
- Proteinplast: Stores proteins.
aMYLOplast = Milo tend the Silo + Starch.
