1.3: Parts of a Cell
What is a Cell Wall? And where is it found?
- (Outer Membrane). It is an additional layer surrounding the cell membrane; it is rigid and for the most part cannot change its shape. -Found in bacteria, plants, fungi, and algae and help the shape of the cell.
What is important to know about Chloroplasts? And what are the site of Chloroplasts?
-Animal cells do not contain chloroplasts. -They are the site of photosynthesis-the process of capturing sunlight and converting it into the usable energy sources ATP and NADPH.
Despite the harsh conditions in which they are found, organisms in this class lack peptidoglycan in their cell walls.
-Archaea.
The peptidoglycan layer is essential for what?
-Bacterial survival as it protects the cell from potentially damaging environmental stresses.
What are double membrane-enclosed organelles specific to algae and plants, and they house the photosynthetic pigment Chlorophyll?
-Chloroplasts.
What is the Cytoplasm? And what is it comprised of?
-Constitutes the open volume within a cell. -Comprised mostly of water containing dissolved substances important in the functioning of the cell.
The membrane of the Endoplasmic Reticulum is?
-Continuous with the nuclear membrane.
What is the term defined as a series of membrane-enclosed sacs and interconnected tubes (lumen)?
-Endoplasmic Reticulum (ER).
What is the function of the Cell Membrane (Plasma Membrane/Cytoplasmic Membrane)?
-To surround the plasma/cytoplasm of the cell.
What are Diatoms?
-A type of algae, and have thick cell walls containing silica (the main component found in glass), making them rigid.
What is a series of interconnected flattened sacs (vesicles) located between the nucleus and cytoplasmic membrane?
-Golgi Complex.
What is a key distinction between Prokaryotic and Eukaryotic cell membranes?
-Is the absence of sterol lipids (such as cholesterol), which play a major role in the Eukaryotic membrane composition.
What are some important things to note about the membrane?
-It has a relatively high degree of fluidity, meaning lipids can move freely within the two layers. -How freely the lipids move is largely dependent on the types of lipids present, the temperature of the environment (lipids are slower at lower temperatures and faster at high temperatures), and the presence of any additional molecules (proteins).
What do Mitochondria contain?
-Tightly packed folded internal membranes called cristae to drastically increase the surface area where chemical reactions occur.
What is the Cell Membrane composed primarily of?
-It is a bilayer composed primarily of amphipathic phospholipids, meaning they contain a polar hydrophilic (water loving) head group and a non-polar hydrophobic (water fearing) tail region. -The lipid bilayer is situated with the non-polar tail groups facing inward, orienting the polar head groups to interact with water both outside and inside of the cell.
What are membrane-enclosed organelles that contain hydrolytic enzymes capable of degrading unwanted cellular debris, such as proteins, lipids, nucleic acids, and polysaccharides?
-Lysosomes.
Yeasts have cell walls composed of?
-Mannoproteins-highly glycosylated polypeptides called mannan and mannose.
This is considered the power house of the cell, it is a double membrane-enclosed organelle primarily responsible for generating ATP, a chemical source of energy within the cell.
-Mitochondria.
Within the nucleus is the what? And what is it?
-Nucleolus, the site of ribosome synthesis.
What is the defining organelle of all Eukaryotic cells and is defined by a porous double lipid layer that contains the genomic content of the cell (DNA)?
-Nucleus.
What are membrane-enclosed structures that perform specific functions?
-Organelles.
What does the bacterial cell wall contain?
-Peptidoglycan, a peptide-polysaccharide matrix.
The Cell Wall plays and important role in?
-Providing support, structure, and protection.
All organisms with the exception of this, are exclusive to Eukaryotic cells.
-Ribosomes.
What organelle is responsible for protein synthesis? And where are they located?
-Ribosomes. -They are located in the cytoplasm of prokaryotic cells and are found attached to the endoplasmic reticulum in eukaryotic cells.
The Endoplasmic Reticulum is composed of?
-Smooth Endoplasmic Reticulum (SER). -Rough Endoplasmic Reticulum (RER).
Some cell walls may contain what? Whereas Fungi contains what?
-Some cell walls contain polysaccharides, like cellulose and pectin, whereas Fungi have cell walls containing cellulose and chitin.
The cell wall is composed primarily of?
-Surface-layer proteins (called an S-layer) that provide both physical and chemical protective barrier to the harsh surrounding environments in which they are found.
The combination of the cell membrane and the outer membrane (cell wall) are referred to as?
-The cell envelope.
What is the Cell Membrane? And what is it often referred to as?
-The cell membrane encloses the main body of the cell. -It is also referred to as the Plasma Membrane and/or Cytoplasmic Membrane.
What kind of barrier does the Cell Membrane have? And what does it mean?
-The cell membrane is a semi-permeable barrier surrounding the cytoplasmic space of the cell. -Semi-permeable means that it allows certain substances to pass through while excluding others. It acts as a barrier to the outside environment while also retaining and preventing the intra (within) cellular components from being lost to the surrounding environment.
The Golgi Complex serves as?
-The distribution center of the cell. Here, the proteins may undergo modifications or be packaged before being distributed.
The Rough (Endoplasmic Reticulum) appearance is due to?
-The presence of ribosomes that stud the ER membrane surface.
What purpose do Lysosomes serve?
-The waste disposal system of the cell.