Cells and Organelles Flashcards
1
Q
Prokaryotic Cells
A
- do not enclose genetic information in a nucleus
- organelles are not membrane bound
- always unicellular
- DNA is circular and found in the nucleoid
- generally smaller and less complex than eukaryotic cells
- Have cell wall (extra layer of protection, shape and prevent dehydration)
- Bacteria cell wall is made up of Peptidoglycan: sugar and amino acids
- Has capsule (attach to surfaces)
- Flagella - locomotion
- Pili - exchange genetic material; during conjugation (Help adhesion)
note: all cells have a cell-membrane, cytoplasm, ribosomes, and genetic material
2
Q
Eukaryotic Cells
A
- genetic information is enclosed in the nucleus
- organelles are enclosed by a plasma membrane
- mostly multicellular, but it is sometimes unicellular
- DNA is linear
- generally larger and more complex
note: all cells have a cell-membrane, cytoplasm, ribosomes, and genetic material
3
Q
Differences Between Plant and Animal Cells
A
- plant cells have a cell wall and chloroplasts
- plant cells have one large central vacuole for water while animal cells have many, smaller vacuoles
4
Q
Organelles
A
- membrane bound sacs within the cell with specialized functions
5
Q
Cell Wall
A
- made up of peptidoglycan or cellulose and provides external support
- protects cell and gives it shape
6
Q
Cell Membrane
A
- separated inside and outside of cell
- selectively permeable
- regulates the diffusion of materials
- Made up of phospholipid bilayer (head is hydrophilic, tail is hydrophobic)
7
Q
Cytoplasm
A
- gel-like cytosol between the nucleus and the plasma membrane
- where all metabolic processes take place.
- Hold organelles in place
8
Q
Cytoskeleton
A
- network of fibers within the cytoplasm that maintains shape of cell
- Secures organelles
- Allows cytoplasm and vesicles to move
- 3 Fibers: Microfilaments, Intermediate filaments and microtubules
- Microfilaments - thin fibers that help move cellular components
- Intermediate filaments - maintaining shape and anchoring organelles
- Microtubules - guide organelle movement, pull chromosomes to their poles
9
Q
Nucleus
A
- houses DNA and directs protein and ribosome synthesis
- Nuclear envelope - double membrane structure (phospholipid bilayer) with pores
- Chromosomes - structures within the nucleus made up of DNA
- Chromatin - the combination of proteins and DNA
10
Q
Nucleolus
A
- assembles the ribosomal subunits (some Chromosomes code for ribosomal RNA)
- Transported out through nuclear pores into cytoplasm
11
Q
Ribosomes
A
- used in protein synthesis
12
Q
Endoplasmic Reticulum
A
- connected membranous tubules that collectively modify proteins and make lipids
- Hollow portion of ER tubules - lumen
- Rough ER - has ribosomes attached to it that synthesizes proteins
- RER creates vesicles and ships the proteins to the golgi body
- Smooth ER - no ribosomes attached and synthesizes carbohydrates, lipids and steroids
- Detoxifies medications and poisons and stores calcium
13
Q
Golgi Apparatus
Golgi Body
A
- series of flat membranous sacs that modify, sort tag, packages and distributes lipids and carbohydrates to proteins made by the ER
- In plants, they synthesize polysaccharides
- Packages in a vesicle and sends it out
14
Q
Vesicles and Vacuoles
A
- membrane bound sacs used for storage and transport
- Vesicles can fuse with other membranes in the cell
- Plant vacuoles break down macromolecules
- Large Central Vacuole - stores water and helps maintain structure
15
Q
Lysosomes
A
- used to break down macromolecules
- recycle organelles
- destroy pathogens through phagocytosis
