Lecture 5.1 Flashcards
What is Cell Theory?
-Cells are the fundamental units of life
-All organisms are composed of cells
-All cells come from preexisting cells
What are the implications of cell theory?
-Functions of all cells are similars
-Origin of life was the origin of cells
-Life is continuous
What size are cells usually?
less that 200um
What kind of microscopes are used to visualize cells?
Electron microscopes (better than light microscopes)
What ratio do cells prefer?
High surface area to volume (3:1)
What does the surface area of a cell determine?
The amount of substances that can pass the cell boundary per unit time.
What does the volume of cells determine?
Determines the amount of chemical activity in the cell per unit time.
What happens when a cells volume increases?
Chemical activity will increase, along with the need for resources and waste removal and surface area becomes limiting, and thus organisms consist
of many small cells.
What are the two domains of Prokaryotic cells?
Bacteria and Archaea
Which organisms are exclusively unicellular?
Prokaryotic cells
What do all prokaryotic cells lack? What do they ALL have?
They lack internal compartments.
They have a nucleus not membrane bound (nucleoid region), plasma membrane, nucleoid region with one circular strand of DNA, cytoplasm containing dissolved enzymes, water, and small molecules and 70S (small) ribosomes for making proteins
What is the organization of Eukaryotic cells?
Protists, Plants, Fungi, and Animals
Which organisms are unicellular or multicellular?
Eukaryotic cells
What do eukaryotic cells have that prokaryotic cells dont?
They have many membrane bound compartments including a double-membrane-bound nucleus containing DNA.
What do SOME prokaryotic cells have?
- outer membrane ( the cell wall)
- capsule (outside cell wall or outer membrane)
- photosynthetic pigments
What do MOST prokaryotic cells have?
• cell wall (outside the plasma membrane) made of peptidoglycan
What is rotating flagella?
It is made of protein flagellin found on some prokaryotics and causes the movement of the cell.
What is pili?
It is hairlike structures projected from the surface of some prokaryotic cells that help bacteria adhere to one another, others cells, or to environmental surfaces a.
What do eukaryotic cells have?
-Plasma membrane
-cytoplasm
-ribosomes
-organelles.
Are all organelles the same?
No, they each have their own specific role in cell function.
What is the largest organelle of a eurkayotic cell?
The nucleus
What surrounds the nucleus?
Nuclear envelope
Where are ribosomes made?
The nucleus
What are the properties of eukaryotic ribosomes?
-they are 80S large
-molecules made of RNA and proteins
-found free-floating or attached to RER
What do nuclear pores do?
They control the movement between nucleus and cytoplasm.
What does chromatin do?
It diffuses within the nucleus, but just before cell division it condenses to form visible chromosomes.
Where is most of the cells DNA found?
In the nucleus
What does DNA associate with to make chromatin?
Protein
