- Unicellular organism
- Has no true nucleus, nuclear envelope, or membrane-bound organelles
ex)bacteria and cyanobacteria
Found in all living things, such as plants and mammels.
Have a true nucleus that contains chromosomes and has a nuclear envelope.
All mammalian cells contain what 3 structures?
- 1. Cell Membrane
- 2. Cytoplasm
- 3. Nucleus
What is the importance of the lipid bilayer that makes up the cell membrane?
- Thin membrane made up of 2 layers of lipid molecules
- Form barrier around cells
Keeps ions, protiens, and other molecules where they are needed and prevents them from diffusing into areas where they should not be.
Oxygen and carbon dioxide molecules can pass through with ease.
Name the types of protiens found on the cell membrane:
create channels that aid in the selective permeability of the cell membrane
- have enzymatic capabilities
- (located on inside of cell's lipid bylayer)
cell to cell recognition (within glycolipids)
intercellular attachments- act as binding cells
Which is more commonly found in mammilian cells: cilia or flagella?
Cillia occur in large numbers.
What are the 4 components of cytoplasm?
Name the types of fibers that make up the cytoskeleton.
- Intermediate Fibers
Name the 6 organelles:
- Endoplasmic Reticulum
- Golgi Apparatus
- powerhouse of the cell
- produces 95% of the energy that fuels the cell
important site for protein synthesis
Rough ER: involved in production of protein
Smooth ER: involved in synthesis and storage of lipids
modification, packaging, and distribution center for molecules
- breakdown nutrient molecules into usable smaller units
- digest intracellular derbis
contains enzymes that use oxygen to detoxify a number of harmful substances including alcohol and formaldehyde
Can a cell that does not contain a nucleus live as long as a cell that does contain a nucleus?
Why or why not?
- Without a nucleus, a cell cannot: divide, make protein or enzymes, or repair themselves as they start to age.
- For this reason, the supply of vital molecules allows them to survive for only 3-4 months.
How do histones play a role in gene regulation?
They keep the DNA strand organized and untangled, and also expose small sections of DNA to the outside nucleoplasm.
They help to determine which segments of the DNA will be expressed and therefore which proteins will be made.
Where is most of the water in animals found?
Inside the animal's cells (intracellular fluid)
It is the kinetic movement of molecules from HIGHER to LOWER concentration.
ex)water, oxygen/carbon dioxide
What 3 principles determine whether a molecule can diffuse or not?
- 1. Molecular Size
- 2. Lipid Solubility
- 3. Molecular Charge
It is the movment of water through a semipermeable membrane from DILUTE to more CONCENTRATED one.
What is another name for hydrostatic pressure in the body?
Excretion vs. Secretion
Excretion: exocytosis (moving stuff out of cell) of waste products
Secretion: exocytosis of manufactured molecules
What are the principal ions involved in maintaining a cell's resting membrane potential?
Sodium and Potassium
Somatic cells divide by what process?
3 Stages that occur during the Interphase of Mitosis
- 1. Growth one (G1)
- 2. Synthetic (S)
- 3. Growth two (G2)
4 Stages of Mitotic phase of Mitosis
- 1. Prophase
- 2. Metaphase
- 3. Anaphase
- 3. Telophase
chromatin becomes visible and organizes into chromosomes by joining 2 strands by a centromere
nuclear envelope and nucleoli also disappear and the centriols divide and replicate, traveling to either "pole" of the cell
newly formed chromosomes align on a medial plane or "equator" between the 2 centrioles located at either end of the dividing cell
the daughter chromosomes begin to migrate to their respective centriols, away from the center of the dividing cell
- daughter chromosomes return to being long-fiber chromatids
- nuclear envelope and nucleoli reappear
- the cell has completed its formation into 2 completely independent daughter cells
What 3 factors play a role in the control of cell devision?
- 1. Normal cells stop dividing when they come into contact with surrounding cells (Contact Inhibition).
- 2. Growth inhibiting substances may be released from cells when their numbers reach a certain point.
- 3. A number of checkpoints are reached during cell division, when the cell reassesses the division process.
Where does protein synthesis begin?
- The nucleus
- (where the instructions for building proteins are contained within the DNA)
What are the nucleotides found in DNA?
What are the nucleotides found in RNA?
The process of transcribing the genetic code from DNA and RNA through protein synthesis using messenger RNA.
Process of protein synthesis using messenger RNA to transfer genetic info in the form of nucleotides into amino acid form.
(occurs in cytoplasm on ribosomes)