Overview of the cell - Cell Functions: Breathe, Produce energy, and communicate. - Cells are divided into two compartments: Cytoplasm and Nucleus - Shape determined by a cytoplasmic skeleton.
Histology Focuses "on how cells' structure and arrangement optimize functions specific to each organ"
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Bio 446L - Exam 1 Questions and
Answers
Overview of the cell ✅- Cell Functions: Breathe, Produce energy, and communicate.
- Cells are divided into two compartments: Cytoplasm and Nucleus
- Shape determined by a cytoplasmic skeleton.
Histology ✅Focuses "on how cells' structure and arrangement optimize functions
specific to each organ"
Scanning Electron Microscope (SEM) ✅A microscope that uses an electron beam to
scan the surface of a sample (3D Structures)
Transmission Electron Microscope (TEM) ✅A microscope that uses an electron beam
to study the internal structure of thinly sectioned specimens. (2D Structure)
Plasma membrane ✅- Separates cytoplasm of cell from extracellular world.
- composed of lipids and two types of proteins
- Lipid Bilayer (hydrophobic inner layer; hydrophylic outer layer)
- Contain integral and peripheral proteins.
- Trilaminar Structure: divide layer of the inside/outside.
Integral or transmembrane proteins ✅Proteins embedded in membrane or passing
through the plasma membrane.
Peripheral membrane proteins ✅Associated with the membrane, but not actually
embedded in it, loosely attached to either side of membrane.
Achondroplasia (dwarfism) ✅- Affects bone growth the receptors are not sending
signals so cartilage does not turn into bone, caused by a mutation (FGFR3) gene.
Glycoproteins ✅Extracellular surface has carbohydrates that are covalently bonded to
proteins.
Glycolipids ✅Membrane carbohydrates that are covalently bonded to lipids.
Glycocalyx ✅Cell coat between the two bi-layers
Lipid rafts ✅-
Cholesterol molecules joined together.
,Transport across membranes ✅- simple diffusion.
- Vesicular transport
Vesicular transport ✅maintains the integrity of the plasma membrane
Endocytosis ✅substance enters the cell
Exocytosis ✅substance exits the cell
Phagocytosis ✅Brings a structure into the cell
Pinocytosis ✅Brings liquids into the cell (digesting)
Receptor-mediated endocytosis ✅One or more transmembrane proteins, wait for a
signal before bringing down the cell.
LDL receptor ✅A protein on the surface of cells that binds to LDL particles and allows
their contents to be taken up for use by the cell. (Phagocytosis)
Cell communication ✅Cells communicate to coordinate their function
- many communicate with adjacent cells via intercellular junctions
1. Endocrine Signaling
2. Paracrine Signaling
3. Synaptic Signaling
Synaptic signaling ✅a nerve cell releases involving neurotransmitter molecules into a
synapse, stimulating the target cell
Chanel linked receptors ✅Ligand binds and opens receptors
Enzymatic receptors ✅-Protein kinase enzymes
-Activated to phosphorylate other enzymes within the cell
-Provides mechanism for altering enzymatic activity
, 2. G-protein binds to active receptor
3. GTP binds to G- proteins and activates. Activated G-protein leaves and attaches to
and activates effector protein
4. Effector protein acts as secondary messenger which leads to protein kinase
activation
5. Kinases phosphorylate other enzymes
Mitochondria ✅- Make ATP & energy of the cell
- Mobile Power Generators of cell they generate energy (ATP)
- Not present in RBC's (Red Blood Cells) and terminal Keratinocytes.
- Abundant in cells that use large amounts of energy.
- Contains a Cristae: folding of inner membrane
Keratinocytes ✅an epidermal cell that produces keratin.
Cristae ✅folds in the inner membrane of mitochondria, increases surface area.
Where would you see a mitochondrial deficient disease have its impact? ✅Muscle,
uses a lot of energy, a deficiency would cause weakness in the person.
Enzymes on inner membrane generate ATP ✅
Aerobic respiration cell involves the ✅Electron transport chain
Endoplasmic Reticulum ✅-A network of interconnecting channels forming the cisterna
which run through cytosol.
- Moves molecules through cisternal space. Stores newly synthesized molecules.G
Ribosomes ✅site of protein synthesis and get signals from the MRNA, assemble
polypeptides
Rough Endoplasmic Reticulum (RER) ✅the region of the endoplasmic reticulum that is
studded with ribosomes and engages in protein modification for secretion, incorporation
into the plasma membrane, and as enzymes within lysosomes.
Smooth Endoplasmic Reticulum (SER) ✅Site of lipid synthesis, and carbohydrate
metabolism. Steroid synthesis and detoxification of drugs and poisons, alcohol.
Golgi apparatus ✅proteins transported here are modified and packaged, shipping
vacuoles to move within cell or be secreted.
Free polyribosomes ✅Proteins in the cell that travel down to other places
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