Module 1 Lecture 1 - Cell Structure and Function Flashcards
(50 cards)
What does Theodor Schwann state about the cell?
- The cell is the smallest structure and functional unit that can carry out life processes
- The activities of each cell depend on specific structural properties (movement, changing shape, abundant in organelles, etc)
- For an organism to function it depends on the collective structure and functions of all the cells within it.
- Cells of all organisms are practically similar in structure and function due to them having to keep the organism alive
- Cell is the basic unit of life
What does it mean when an organism depends on the collective structure and function of all the cells
It means that each cell is unique and provides something important to the organism
i.e. Immune cells provide immunity, skin cells provide us with skin, adipose cells provide us with fat to keep warm, etc.
What are the only exceptions to not having a cell?
Viruses and prions
How many different types of cells are there? List some examples
200 types of cells - immune cells, reproductive cells, smooth muscle cells
How many total cells are in the human body (not classified into)?
Trillions of cells (not classified into separate types of cells)
Three common/shared features of every cell?
Contain: nucleus, cytosol, and plasma membrane
How does the plasma membrane look?
Thin and membranous
Purpose of the plasma membrane?
To act as a barrier/boundary by keeping each cell enclosed/protected while providing a fixed environment inside the cell
What is the plasma membrane composed mostly of?
Lipid (fat) bilayer
What is the plasma membrane studded with?
It has proteins studded around the membrane
What is the purpose of the proteins on the plasma membrane
Helps facilitate movement of molecules in and out of the cell
Why is the plasma membrane known to be selectively permeable?
Although it acts as a barrier, it allows for certain nutrients and molecules to move through; hence being selective
What is the Nucleus?
The nucleus is the “brain” of the cell because it holds the genetic material of the cell that allows for duplication
Where is all the genetic information encoded in order to make proteins?
Nucleus
DNA stands for?
Deoxyribonucleic acid (no oxygen attached to the carbon atom)
What is the Endoplasmic Reticulum?
Large organelle; a connected mesh/network of a fluid filled membranous system
Purpose of the Endoplasmic Reticulum?
To produce proteins and lipids
How does transcription work?
1) DNA begins to unwind due to RNA polymerase and pre-mRNA transcript is made.
2) pre-mRNA is processed into mRNA and it sent out of the nucleus into the cytosol
How does translation work?
1) After leaving the nucleus it attaches to a ribosome which has rRNA and proteins
2) Ribosome moves down the mRNA while reading it and tRNA molecule one by one brings amino acids creating a polypeptide chain
Features of Rough ER
Studded with ribosomes (helps mRNA turn into a protein)
What does the Rough ER do?
Creates proteins to be released outside the ER or keep it inside the plasma membrane or for other cell components
Feature of Smooth ER
Does not have ribosomes but it has reticular like tubules for an increased surface area
Role of the Smooth ER
Package the secretory product (proteins from the rough er) into transport vesicles; bud off to the Golgi complex
What does the golgi complex look like?
Stack of flattened, slightly curved, bounded by the membrane
