Chapter 4 quiz Flashcards
What is cell fractionation? What is the purpose of it
A process that breaks up the cells and separates he components using centrifugation. This enables scientists to determine the functions of organelles
What are the characteristics of prokaryotic cells?
- No nucleus
- DNA in an unbound region called the nucleoid
- No membrane-bound organelles
- Cytoplasm bound by plasma membrane
What are the basic features of all cells?
- Plasma membrane
- Semifluid substance called cytosol
- Chromosomes
- Ribosomes
What is the plasma membrane?
A selective barrier in a cell that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell, made up of a phospholipid bilayer
What are the characteristics of Eukaryotic cells?
- DNA in the nucleus that is bounded by a membranous nuclear envolope
- Membrane-bound organelles
- Cytoplasm in the region between the plasma membrane and nucleus
- Generally larger the prokaryotic cells
What is the nucleus and what surrounds it?
The nucleus contains most of the cells genes and is usually the most conspicuous organelle. It is surrounded by the nuclear envelope, which is made up of 2 nuclear membranes that are lipid bilayers
What are ribosomes?
Ribosomes use information in the DNA to make proteins. The are complexes of ribosomal DNA, and ribosomes are proteins themselves
What is the nuclear lamina?
The structure that maintains the shape of the nucleus, it is composed of protein and adds support
Where do ribosomes carry out protein synthesis? What are these different type of ribosomes called?
- In the cytosol(free ribosomes)
2. On the outside of the endoplasmic reticulum or nuclear envelope(bound ribosomes)
What are chromosomes and what makes them up?
Chromosomes are he discrete units that DNA is organized into in the nucleus. Chromosomes are made up of DNA and proteins called chromatin
When and how does chromatin condense?
Chromatin condenses to form discrete chromosomes as a cell prepares to divide. The DNA wraps around the like a spool
What is the nucleolus?
The site of ribosomal RNA(rRNA) synthesis inside the nucleus
What is the endoplasmic reticulum and its characteristics?
The ER membrane is continuous with the nuclear envelope. It is made up of the smooth ER(lacks ribosomes) and rough ER(surface is studded with ribosomes). It takes up a lot of the cell and acts as a biosynthetic factory
What is the purpose of the endomembrane system?
To regulate protein traffic and perform metabolic functions in the cell
What are the 2 ways the endomembrane system stays connected?
- Continuous: No vesicles
2. Connected by vesicles
Why is the ER folded?
To save space and be efficient
What are vacoules?
Large vesicles
What makes up vesicles?
Lipid bilayers
What is the golgi apparatus?
An organelle that:
- Manufactures certain macromolecules
- Modifies products of ER
- Sorts packages materials into transport vesicles
The golgi apparatus consists of flattened sacs called cisternae
What is the function of the rough ER
- Secrete glycoproteins from bound ribosomes
- Distribute transport vesicles
- Membrane factory for cell