Can be divided into cytosol, cytoplasmic organelles and inclusion bodies (non-living accumulations of material ie lipid droplets)
What percentage of cytosol is water with other components?
What percentage of the cell volume is the cytosol?
What components can you find in the cytosol?
Large organic molecules (proteins, carbos, lipids)
Small organic molecules (simple sugars and ions)
Site of many important chemical reactions
-production of ATP, synthesis of building blocks
What are they?
Membranous organelles surrounded by one or two lipid bilayer membranes - help separate functions
Some are non-membranous and are in direct contract with cytoplasm
Large organelle with double membrane nuclear envelope
Outer membrane is continuous with rough ER
Perforated by water-filled nuclear pores
Why are there water-filled nuclear pores on the nucleus?
To allow active transport of large proteins and ribosomes
Spherical, dark bodies within the nucleus (no membrane)
Site of ribosome assembly
Where are genes found?
What are genes?
Directions for a specific protein
What do non-dividing cells contain?
-loosely packed DNA
What do dividing cells contain?
What do chromosomes contain?
Tightly packed DNA
What does it mean that some cells are anucleate? (eg RBC's)
What does it mean that some cells are multi-nucleate? (eg skeletal muscle)
What do free ribosomes do?
They are loose in the cytosol to synthesize proteins found inside the cell
What are membrane-bound ribosomes attached to?
Attached to endoplasmic reticulum (ER) or nuclear membrane
What synthesizes proteins needed for plasma membrane or for export?
What is transciption?
Transcribe DNA information onto a messenger RNA molecule (mRNA)
What is translation?
the mRNA translates the "message" into a sequence of amino acids in order to build a protein molecule
What type of RNA carries amino acids to ribosomal RNA (rRNA) for protein synthesis?
Transfer RNA (tRNA)
True or false: Amino acids = protein
Network of membranes forming flattened sacs or tubules called cisterns
Continuous with nuclear envelope and covered with attached ribosomes
Synthesizes, processes and packages proteins for export
Synthesizes phopholipids, steroids and fats
Detoxifies harmful substances (alcohol)
Calcium storage in muscle cells
Comprised of 3-20 flattened, curved membranous saces called cisterns
Which side of the Golgi Complex faces the ER? Convex or concave
Convex side faces ER
Concave side faces cell membrane
Processess and packages proteins produced by rough ER
How to proteins pass from rough ER to golgi complex?
via transport vesicles
What are the three cisterns of the Golgi Complex?
Processed proteins pass from entry cistern to medial cistern to exit cistern in transfer vesicle
What types of vesicles do finished proteins exit golgi as?
Storage Vesicle (lysosome)
Formed in Golgi complex
Filled with digestive enzymes
Digests foreign substances
Recycles own organelles
Membranous vesicles that:
Smaller than lysosomes
Contain enzymes that oxidize organic material
Part of normal metabolic breakdown of amino acids, fatty acids and free radicals
Oxidizes toxic substances such as alcohol and formaldehyde, usually found in the liver and kidneys
Very small vesicles that contain proteases for digestion of proteins
Double membrane organelle
Central cavity known as matrix
Inner membrane folds known as crista
Generation of ATP
Powerhouse of cell
This increases with need for ATP
Network of protein filaments throughout the cytosol
Cell support and shape
Organization of chemical reactions
Cell and organelle movement
Thinnest filaments (actin) in the cytoskeleton
Locomotion and division
Several different proteins
Strengthen and shape
Large clindrical structures composed of tubulin
Flagella, cilia, and centrosomes
Play a role in transport
Motile projections of cell
Bundles of Microtubules
Cilia and Flagella
State the two differences between cilia & flagella
Cilia: short and multiple
Flagella: longer and single
Found near nucleus
2 Centrioles (90 degrees to eachother)
Consist of bundle of microtubules
Role in formation of cilia and flagella
Formation site for mitotic spindle and microtubules
Aggregates of non-living organic molecules in the cytosol
Diverse in composition, shape and longevity
Examples include granules of melanin (in skin), glycogen (in liver) and lipid droplets (in fat cells)
4 Theories to explain aging:
1. Cells have limited number of divisions
2. Autoimmune responses due to changes in cell identity markers
3. Free radical theory (electrically charged moleculres with an unpaired electron cause cell damage, more metabolism more free radicals)
4. Genetic telomere theory
theory of aging: structures on ends of chromosomes get closer as DNA replicates (some nucleotides lost) and eventually stop replicating. Telomerase prevents telomeres from degrading by adding more repeating DNA-used in cell cultures, endless replication observed, called immortality enzyme
Genetic telomere theory
Increased number of cell division
True or false: a benign tumor does not metastisize or spread.
Spreads due to cells that detach from tumor and enter blood or lymph
Causes of cancer
Carcinogens, x-rays, viruses
Why is there cancer?
Every cell has genes that regulate growth and development
Mutation in those genes due to radiation or chemical agents causes excess production of growth factors