Chapter 3 Cell Flashcards
the basic functional unit of life
Cell
Two general classes of cell
-Sex Cells (Gametes)
-Somatic Cells
-Reproductive cells with half the number of
chromosomes
* Male sperm
* Female oocyte (a cell that develops into an egg)
Sex Cells (gametes)
a cell that develops into an egg
Female oocyte
Body cells with a full set of chromosomes
* Soma = body; All body cells except sex cells
Somatic Cells
Functions of the Plasma Membrane
-Barrier providing physical isolation
-Regulation of Exchange with the Environment
-Sensitivity to the Environment
-Structural Support
Phospholipid bilayer
Plasma Membrane
is primarily made of lipids
Membrane
Membrane Proteins:
- Anchoring Proteins-Stabilizers
- Recognition Proteins-Identifiers
- Enzymes- Catalyze reactions in cytosol or extracellular fluid
*Receptor Proteins- Bind and respond to ligands (ions, hormones)
*Carrier Proteins- Transport specific solutes through membrane
- May require ATP
*Channels- Allow water and specific solutes through membrane
All materials inside the cell and
outside the nucleus
Cytoplasm
- (intracellular fluid)
-Contains dissolved nutrients, ions, proteins, waste
products
-Compared to Extracellular fluid, has: - High potassium/low sodium
- High protein
- Contains carbohydrate, amino acid, lipid
reserves
Cytosol (intracellular fluid)
intracelullar Structures with specific functions or tiny organs
Organelles
2 kinds The Organelles
*Nonmembranous organelles
* No outer membrane
* Six types include: cytoskeleton, microvilli, centrioles, cilia,
ribosomes, and proteasomes
- Membranous organelles
- Covered with plasma membrane (Isolated from cytosol)
- Include the endoplasmic reticulum (ER), the Golgi apparatus,
lysosomes, peroxisomes, and mitochondria
- No outer membrane
- Six types include: cytoskeleton, microvilli, centrioles, cilia,
ribosomes, and proteasomes
Nonmembranous organelles
- Covered with plasma membrane (Isolated from cytosol)
- Include the endoplasmic reticulum (ER), the Golgi apparatus,
lysosomes, peroxisomes, and mitochondria
Membranous organelles
Cells skeleton that gives shape, strength, attachment
Cytoskeleton
cytoskeleton includes
-microfilaments
thin/smallest( actin) for movement
-intermediate filaments
thick/medium sized( keratin, collagen)
-microtubules
largest( kinesin & Dynein) hollow tubes of tubulin
Myosin protein
Muscle Cells
-thin filaments composed of the protein
actin
-Provide strength, attach plasma membrane to cytosol
- Determine consistency of cytoplasm
-Pair with thick filaments of myosin for movement
Microfilaments
mid-sized between microfilaments and thick filaments;
* Durable and insoluble (Keratin, collagen)
Function:
* Strengthen cell and maintain shape
* Stabilize position of organelles
* Stabilize cell position in a tissue
Intermediate filaments
Large, hollow tubes of tubulin; attach
to centrosome and extend outward
* Strengthen cell
* Anchor organelles and provide “railway” for organelles
and vesicles to move along
Microtubules
are proteins that move organelles
Kinesin and Dynein
Finger like projections of plasma membrane
* Increase surface area for absorption (GI Tract)
Microvilli
- Cylinders of microtubules (9 microtubule triplets, no central)
- form spindle apparatus during cell division
Centrioles
cytoplasm surrounding pair of centrioles, where
cytoskeleton begins
Centrosome
Thin hair-like extensions (9 microtubule pairs, 1 central pair)
-move fluids across the cell surface
Cilia
Consist of 2 subunits that function to produce
polypeptides (proteins)
-Small ribosomal subunit and Large ribosomal
subunit
-Both must join along a strand of mRNA for protein
synthesis to occur
Ribosomes
2 Two types of Ribosomes
- Free ribosomes in cytoplasm
* Manufacture proteins for cell - Fixed ribosomes attached to ER
* Manufacture proteins for secretion
Contain enzymes
(proteases)
*Disassemble damaged
proteins for recycling
Proteasomes
No ribosomes attached
* Synthesizes lipids
* Cholesterol for use in membranes
* Steroid hormones in the reproductive system and
endocrine system
* Detoxifies alcohol, drugs
* Calcium Storage
Smooth endoplasmic reticulum (SER)
Surface covered with ribosomes
* Active in protein modification and folding polypeptides
into complex structures
* Glycoprotein synthesis
* Phospholipid synthesis for membranes
* Encloses products in transport vesicles
Rough endoplasmic reticulum (RER)
Flattened disc-like cisternae
* Functions
* Synthesize carbohyrates
* Finishing touches on proteins and glycoproteins
* Packages compounds in vesicles
* Become lysosomes
* Fuse with plasma membrane to re-plenish
phospholipids
* Release contents through exocytosis
Golgi Apparatus
-in cytoplasm
-Manufacture proteins for cell
Free ribosomes in cytoplasm
- attached to ER
- Manufacture proteins for secretion
Fixed ribosomes
