chapter 4 Flashcards
Nucleus,
Nuclear Envelope,
Nucleolus
- Nucleus is the “chief executive” of the cell.
- Genes in nucleus store info needed to mkae proteins
- Nuclear Envelope is a double membrane boardering nucleus. Pores in the envelope allow materials to move between the nucleus and cytoplasm, liek mRNA for protein synthesis
- Nucleolus is inside the nucleus, is where ribosomes are made.
Chromatin
fibers formed in the nucleus by long DNA molecules and associated proteins. usually invisible
Chromosome
each long chromatin chain constitutes one chromosome. the number of chromosomes depends on species.
- wrapped, coiled, and super coiled.
- visible
Cell theory
All living things are composed of cells
All cells come from other cells
What are the 2
categories of cells
Prokaryotic- bacteria and archaea
Eukaryotic- plants, fungi, and animals
What do all cells have in common?
All bound by plasma membrane All ave DNA and Ribosomes, tiny structures that build proteins
How are Prokaryotic celld different from Eukaryotic cells?
Prokaryotic cells are Older, smaller, don’t have internal structures surrounded by membranes, no nucleus, rigid cell wall
How are Eukaryotic cells different from Prokaryotic cells?
Eukaryotic cells:
- Have organelles
- Has a nucleus
- Bigger
Cytoplasm
Region between nucleus and plasma membrane. contains all the organelles suspended in fluid
What do plant cells have that anial cells don’t?
Have:
- Protein cell walls made primarily of cellulose
- Chloroplast, converts light energy into chemical energy of food
- Large vacuoles that store water, salt, and minerals
What do Animal cells have that plant cells don’t?
Centrioles and Lysosomes
Cell membranes are made mostly of…..
Lipids called Phospholipids Protiens
- surface binding and transport proteinds regulate traffic across membrane.
- Lipids make a 2 layered membrane called phospholipid bilayer. Has a fatty acid tail (nonpolar/hydrophobic) and a phosphate head (polar/hydrophillic)
Cytoskeleton
- network of dynamic fibers extending throughout the cytoplasm
- provides mechanical support to the cell
- maintains shape
Microtubules and Intermediate filaments and microfilaments
- Straight and hollow, guides the movement of organelles and chromosomes
- plays a role in cell division by forming the mitotic spindle
- Intermediate filamnts and microfilaments are thinner and solid
A cell membrane is called a “fluid MOsaic” because….
“fluid” because molecules can move freely past one another “mosaic” because of the diversity of proteins in the membrane
Endomembrane System What it is how organelles are connected in system what organelles are part of the system?
maufactures and distributes cellular products. organelles that are a part of this system areinterconnected either:
- directly
- through the transfer of membrane segments between them, transport vessicles. system includes Nuclear Envelope, Golgi, ER’s, Lysosomes, Vacuoles, Plasma Membrane
Ribosomes
Responsible for protein syntheis/Translation Made in nucleus but assembled in cytoplasm May assmble proteins suspended in Cytoplasm (synthesized for use in cell) or attached to outside of E.R. (synthesized for use in membrane or export from cell)
Central Vacuoles
Found in plants Store nutrients Absorb water May contain pigments or poisons
Golgi Apparatus
Works witht he E.R. Received, refines, stores, and distributes chemical products of the cell Receives transport vesicle from rough ER, refines, then is put in a new transport vesicle from Golgi
Vacuoles
membranous sacs that bud from the E.R., golig, and plasma membrane. Contractile vacuoles of protists pump out excess water int he cell uses ATP to deal with constant osmotic movement
Endosymbiosis
Evidence that mitochondria and chloroplasts evolved from free-living Prokaryotes in the distant past. Evidence is that mitochondria and chloroplasts contain their own DNA and incharge of own replication
Mitochondria and the structure of Mitochondria
Found in almost all Eukayotic cells Site of Cellular Respiration contain their own DNA and incharge of own replication number of mitochondria depends on the functions of cell Envelope of 2 membranes, a smooth outer membrane and an inner membrane with numerous infoldings called cristae that have enzymes for cellular respiration
Smooth E.R.
No surface ribosomes Produces lipids, including steroids Helps liver cells detoxify circulating drugs
Chloroplasts and their 3 major compartments
Organelles that preform photosynthesis (convert solar energy to chemical energy) most of the living world runs on the energy of photosynthesis 3 major compartments: Space between 2 membranes Stroma, thick fluid in chloroplast Space within grana, the structures that trap light energy and convert it to chemical energy
Endoplasmic Reticulum
- one of the main manufactureing facilities in a cell
- produces an enormous variety of molecules
- compsed of smooth and rough E.R.
Lysosomes
- A sac of digestive enzymes found in animal cells
- Can break down large molecules such as proteins, polysaccharides, fats, and nucleic acids
- Can also destroy bacteria How it works: engulf food in food vacuoles, vacuoles fuse w/ lysosomes, food enzymes digest food, small molecules from digestion leave lysosome and nourish cell. Ths process is also used to rid of damaged cell molecules.
Rough ER
Called “rough” because of the ribosomes that stud the surface that create membrane proteins and secretory proteins After the rough ER synthesizes a molecule, it packages the molecule into transport vesicles that then go to the golgi apparatus, which then go to the membrane for export, called Exocytosis
Cell Walls
in plants only made of cellulose protects the cell maintains cell shape keeps cells from absorbing too much water
How does DNA direct protein production?
- transfers its coded information into message RNA (mRNA)
- mRNA exits nucleus through pores in nuclear envelope
- a ribosome moves along the mRNA translating the genetic message into a protein with a specific amino acid sequence think of it as the ribosome is a scanner, mRNA is white paper, and you copy the text onto the green paper of protein, because theboss only accepts green paper
Cilia and Flagella
Both aid in movement
- flagella propels in a hp-like motion
- cilia moves n a coordinated back-and-forth motion
- both have same basic architecture
- cilia may extend fromnonmoving cells
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