Chapter 4 - biology of the cell Flashcards
Eukaryotic cells are composed of what 3 parts?
- Cytoplasm - a gelatin-like substance, plus structural fibers and organelles
- Nucleus - contains the genetic library of the cell 3. Plasma membrane
- Plasma Membrane
what does the cytoplasm contain?
- contains all the cellular contents between the plasma membrane and the nucleus.
- cytosol (fluid portion) composed of mostly water -organelles are embedded in cytosol
What is the cytoskeleton composed of?
- made up of dense fibres (organelles attached)
1) Microfilaments - actin (makes up muscles)
2) Intermediate filaments - structure
3) Microtubules - Cilia and flagella
what are cilia
short, hair like projections from the cell surface -used to move fluids along the surface
what are flagella
-longer projections that are capable of moving an entire cell Ex) tail of sperm cell
what is the function of ribosomes?
make proteins
what is the function of the Endoplasmic Reticulum, and what does it contain?
-Connection to nuclear envelope 1)Rough ER (have ribosomes) -Produces protein 2)Smooth ER (no ribosomes) -Synthesize fatty acids and steroids
what is the function of the Golgi Complex?
membranous sacs Pack proteins for transport
What is the function of the Mitochondria?
the “powerhouses” of the cell Generates ATP
What is the function of Lysosomes?
contain digestive enzymes
What is the function of Peroxisomes?
detoxify toxic substances (alcohol)
What is the function of Proteasomes?
break down proteins
What is the purpose of the nucleus?
contains DNA in molecules called chromosomes
what is gene expression?
the process of:
1) Transcription: In nucleus, DNA –> pre-mRNA –> mRNA (exits nucleus)
2) Translation (convert mRNA to Protein)
In cytosol mRNA is read, tRNA adds amino acids to form a protein
