Cells Flashcards
What is the function of the surface area in a cell?
It determines the amount of substances that can pass the cell boundary per unit time.
What is the function of volume in a cell?
It determines the amount of chemical activity in the cell per unit time
Prokaryotic cells are a part of which domains?
Bacteria and Archaea
In Bacteria and Archaea, what are the characteristics of the organisms?
-Unicellular
-Lack of internal compartments
-nucleus that is not membrane-bound (nucleoid)
What is the domain of eukaryotic cells?
Eukarya
What are the 4 kingdoms of Eukarya?
Protist , Plants, Fungi and Animal
What are the characteristics of the organisms in Eukarya?
-Unicellular or multicellular
-Many membrane-bound compartments
-Has a nucleus
What do all prokaryotic cells have (constitution)?
-Plasma membrane
-Nucleoid region with one circular strand of DNA
-Cytoplasm containing dissolved enzymes, water, and small molecules
-70S (small) ribosomes for making proteins
What do most prokaryotes have?
-Cell wall (outside the plasma membrane) made of peptidoglycan
What do some prokaryotes have?
-Outer membrane (outside the cell wall)
-Caspsule (outside cell wall or outer membrane)
-Photosynthetic pigments (i.e., cyanobacteria)
What are flagella made for and made of?
-Cause movement of the cell
-Made of flagellin
What are pili for?
Help bacteria adhere to one another, to other cells, or to environmental surfaces
What differentiates eukaryotic cells from prokaryotic cells?
-Much larger (10X)
-Have organelles
What are the 2 main cells?
Animal and plant cells
What is usually the biggest organelle in the eukaryotic cell?
nucleus
What surrounds the nucleus?
The nuclear envelope (phospholipid bilayer)
Where in the nucleus are ribosomes made?
Nucleolus
Which size are the eukaryotic ribosomes?
80S
What are ribosomes made of?
RNA and proteins
Where can ribosomes be found?
Free-floating or attached to RER
What the job of nuclear pores?
Control what goes in and out of the cell
Which organelles have DNA?
Nucleus (most of DNA), mitochondria and chloroplast
DNA associates with protein to form what?
Chromatin
What does chromatin do?
It condenses to form chromosomes when getting ready for cell division
What constitutes the endomembrane system?
-All membranes
- Plasma membrane
- Nuclear envelope
- Endoplasmic reticulum
- Golgi apparatus
- lysosomes
Why is the rough endoplasmic reticulum described as “rough”?
It has 80S ribosomes on its surface (since ribosomes means make proteins)
What is the RER’s role in the cell?
- Make proteins
- Modify proteins
- Fold proteins
- Transport proteins to other regions
What is SER’s role in the cell?
- Make lipids
- Some detoxification
What composes the Golgi apparatus?
- flattened sacs (cisternae)
- Small vesicles
What does the Golgi apparatus do?
- Receives proteins from RER and modifies them more
- Packages and sorts proteins
- In plants, uses polysaccharides to make cell walls
What happens in the cis region of the Golgi apparatus?
Receives vesicles
What happens in the trans region of the Golgi apparatus?
Releases vesicles
What happens in the lysosomes?
There are digestive enzymes that hydrolyze macromolecules into monomers
Where are primary lysosomes made?
In the Golgi apparatus
How does food come in the molecule?
Food (from outside of the molecule) enters the cell by phagocytosis, forming a phagosome
How are secondary lysosomes formed?
Phagosomes + primary lysosome=secondary lysosome
What is the meaning of exocytosis?
Getting wastes out of the cell
Facts about mitochondria:
- double-membrane bound
- 1 circular strand of DNA
- 70S ribosomes
- Makes ATP
What is ATP?
An energy-rich molecule
In what organisms can chloraplast be found?
Plants and photosynthetic protists
Facts about chloroplast:
- Double-membrane bound
- One circular strand of DNA
- Do phostosynthesis
Where can vacuoles be found and what are they for?
They can be found in plants and alga cells and they store water in the cells
What is the cytoskeleton for?
Provides:
- strength
- shape
- movement
What are the proteins that compose the cytoskeleton?
- Microfilaments
- Intermediate filaments
- Microtubules
What are microfilaments made of and what are their role?
- Made of actin
- Provide movement and strengthen the cellular structure
What are intermadiate filaments made of and what are their role?
- Made of keratin
- Provide strength to the cell attachments
What are microtubules made of and what are their role?
- Made of tubulin
- Provide movement (push and pulling)
How are cilia and flagella made?
Microtubules in a 9+2 pattern
How are cilia and flagella anchored on the cell?
With a basal body made of microtubules in a “9triplets”
What type of movement does cilia provide?
short stiff power strokes
What type of movement does flagella provide?
Snake-like movement
What composes centrioles?
“9triplets” of microtubules
What is the role of centrioles in the cell?
Formation of the mitotic spindle
What is called a pair of centrioles?
Centrosome
Where do chromosomes attach during cell division?
mitotic spindle
What is extracellular matrix?
Anything that is outside the cell
What is the extracellular matrix for the plant?
Cell wall made of cellulose
Fungi’s cell wall are made of what?
Chitin
How are cell walls important for water organisms?
Helps withstand high osmotic pressure
What is the extracellular matrix of animals?
Protein collagen and other glycoproteins
