Inside the Cell Flashcards
- is the fluid that fills a cell
- Cell contents
- Gel-like mixture
- Surrounded by cell membrane
- Contains hereditary material
- Includes organelles and cytosol
- Excludes nucleus
Cytoplasm
- Maintains shape of cell
- Positions organelles
- Changes cell shape
- Includes: microfilaments, intermediate filaments, microtubules
Cytoskeleton
- is a small set of microtubules arranged in a specific way
- are found in pairs and move towards the poles (opposite ends) of the nucleus when it is time for cell division
Centrioles
Are Two centrioles arranged perpendicular to each other
- Composed of microtubules: 9 clusters of 3 (triplets)
Centrosome
Composed of tubulin that grows the mitotic spindle
Pericentriolar material
Function: moves chromosomes to ends of cell during cell division
Centrosome
- Made within the nucleus (in nucleolus)
- Sites of protein synthesis
- Consist of ribosomal RNA (rRNA) + proteins
- Contain large and small subunits
- Can be attached to endoplasmic reticulum or free in cytosol
Ribosomes
are Specialized for motion
Cilia and Flagella
- single tail like structure on sperm
- Propels sperm forward in reproductive tract
Flagellum
- in groups
- Found in respiratory system: move mucus
Cilia
- Structure: network of folded membranes
- Functions: synthesis, intracellular transport
Endoplasmic Reticulum
The double membranes of smooth and rough ER form sacs called
cisternae
2 Types of Endoplasmic Reticulum
o Rough ER
o Smooth ER
The Endoplasmic Reticulum that is studded with ribosomes (sites of protein synthesis)
o Rough ER
The Endoplasmic Reticulum that lacks ribosomes
o Smooth ER
Functions:
▪ lipid synthesis
▪ release of glucose in liver cells into bloodstream
▪ drug detoxification (especially in liver cells)
Smooth Endoplasmic Reticulum
Is in charge of storage and release of Ca2+ in muscle cells where smooth E.R. is known as?
Sarcoplasmic Reticulum or SR
- Protein ‘packaging plant‘
- was named after Camillo Golgi, an Italian biologist
Golgi Complex
- Structure: Flattened membranes (cisternae) with
bulging edges (like stacks of pita bread) - Functions: gathers simple molecules and combines
them to make molecules that are more complex
o Move materials within and out of the cell
Golgi Complex
▪ Modify proteins → glycoproteins and lipoproteins that:
▪ Become parts of plasma membranes, Are stored in lysosomes (cell digestion machines) or are exported by exocytosis.
Golgi Complex
Contains digestive enzymes
* Digestive ‘plant’ for proteins, fats, and carbohydrates
* Help in final processes of digestion within cells
Lysosome
Carry out autophagy (destruction of worn out parts of cell) and death of old cells (autolysis)
Lysosome
A hereditary disorder; one missing lysosomal enzyme leads to nerve destruction
Tay-Sachs
True or False:
Cell breaks down if lysosome explodes?
True
2 Types of Small Bodies
Peroxisomes
Proteasomes
o hold on to enzymes that require oxygen
(oxidative enzymes)
o break down fatty acids, digest alcohol and protect cells against hydrogen peroxide
o detoxify; abundant in liver
Peroxisomes
o digest unneeded or faulty protein
(proteolysis)
o Faulty proteins accumulate in brain cells in persons with Parkinson or Alzheimer disease
Proteasomes
Structure:
- Sausage-shaped with many folded membranes (cristae) and liquid matrix containing enzymes
- Have some DNA, ribosomes (can make proteins)
Mitochondria
Function:
- Nutrient energy is released and trapped in ATP; so known as “power houses of cell”
- Produces energy through chemical reactions – breaking down fats & carbohydrates
- Controls level of water and other materials in cell
- Recycles and decomposes proteins, fats, and carbohydrates
Mitochondria
- Directs cell activities
- Separated from cytoplasm by nuclear membrane
- Round or oval structure surrounded by nuclear
envelope with nuclear pores
Nucleus
makes ribosomes that pass into cytoplasm through nuclear pores
Nucleolus
Store genetic material (DNA) in genes arranged in 46 chromosomes
Nucleus
True or False:
DNA contains information for directing protein synthesis:
o In this cell
o In new cells (formed by cell reproduction)
True
• is the suspension fluid that holds the cell’s chromatin and nucleolus
• It is not always present in the nucleus
Nucleoplasm
True or False:
When the cell divides, the nuclear membrane dissolves and the nucleoplasm is released. After the cell nucleus has reformed, the nucleoplasm fills the space again?
True
• Surrounds nucleus
• Made of two layers
• Openings allow material to enter and leave nucleus
Nuclear Membrane or Envelope
• Inside nucleus
• Contains RNA to build proteins
Nucleolus
