Cells Unit Flashcards
Cytoplasm
- 80-90% water
- function: fluid supporting the organelles
Nucleus and nucleolus
-structure: chromosomes (proteins and DNA) surrounded by a nuclear membrane with pores
-function: DNA stores code of genetic info
Determined which proteins cells should make
Nucleolus
- dark section in nucleus
- lots of activity: site of RNA and ribosome manufacturing
Mitochondria
- outer membrane, crustal membrane (inner folds), matrix (inside the cristae)
- function: powerhouse of cell = site for aerobic respiration = make ATP
Chloroplasts (plastids)
- stacks of thylakoids surrounded by double membrane
- function: photosynthesis
Ribosomes
- made of rRNA and proteins (made in the nucleolus)
- function: site of protein synthesis (amino acids)
Endoplasmic Reticulum
- interconnected membranes
- function: importing and exporting materials
Rough ER
-involved in protein synthesis
Smooth ER
- produces lipids
- stores and releases calcium (for muscle contractions)
- helps detoxify chemicals in the liver
Golgi Bodies
- structure: flattened cup shape membranes
- function: packages materials (proteins) for the cell to export
- found in high numbers in cells that secrete, example: enzymes from cells near digestive system
- helps make lysosomes
Lysosomes
-membrane bound sacs of digestive enzymes
-if lysosomes break down
•lysis –> kills the cell
•important for finger/toe development, tail absorption in a tadpole, etc
Peroxisomes
-breaks down hydrogen peroxide (H2O2), poison to cells
Vacuoles
- structure: a space filled with water and dilutes surrounded by a membrane
- function: holds waste, food, or water
- large in plant cell, small in animal cell
Proteins
- act as anchors in cell membrane
- relative position of proteins causes movement
Cytoskeleton
-protein fibers that support and hold cell structures in certain places
Microtubules
-involved in attachment of chromosomes during cell division
Centrioles
- found in pairs
- cylindrical organelles involved in pulling on micro tubules in cell division
Flagellum
- threadlike projection
- complex arrangement of microtubules
Cilia
- shorter hair like structures
- found in rows and mats
- in Protists: movement
- animals: in your lungs
Cell walls
- found in bacteria, fungi, and plants
- rigid support and protection for cells
Cell membrane (plasma membrane)
- phospholipid bilayer and proteins
- lipid: hydrophobic
- phosphate group: hydrophilic
- function: selectively permeable
