Prokaryotic/ Eukaryotic
What cell type would have its genetic information (DNA) stored in the nucleoid?
Prokaryotic
Endoplasmic Reticulum (Smooth and Rough ER), Golgi Apparatus, and the vesicles
Differentiate between endocytosis and exocytosis
Endocytosis: material is taken into the cell
example: lysosome
Exocytosis: material is exported out of the cell
example: insulin secretion
What is the fluid mosaic model?
Describes that the plasma membrane is fluid, phospholipid bilayer is like a "lake" and molecules are "floating" around
How is plasma membrane fluidity regulated? Why is it bad for the membrane to be too fluid or too tight?
Too fluid: add more long fatty acid chains, less unsaturations (if too fluid it will fall apart)
Too tight: add more short fatty acid chains, more unsaturations (will not permit proteins to flex if too tight)
What are the five characteristics of life?
1. Complexity and organization (requires energy to actively maintain)
2. Responds to environment (homeostasis) maintaining constant internal conditions
3. Growth and metabolism
4. Reproduction/ heredity
5. Evolve
What are the key structural components of the nucleus?
nuclear envelope: double lipid bilayer membrane
nuclear pores:passage through nuclear envelope that regulates nuclear transport
nucleolus: ribosomes assembled
nucleus contains chromatins
What is a lysosome and what is the function? Differentiate between a primary and secondary lysosome.
A membrane bound vesicles that contains digestive enzymes.
Function: digest material from outside the cell or from inside the cell (ex worn out organelle)
Primary: new lysosome budding off trans face
secondary: primary fused with endocytic vesicle or cellular organelle
What experiment was used to determine the plasma membrane is fluid?
Cell fusion experiment:
membranes proteins of two cells were stained and fused together. The colors mixed together
What are the kinetics of channel proteins and carrier proteins
channel: linear
carrier: saturations (kinks)
Name the two major cell types. What are some similarities and differences between the two?
Prokaryotic: Bacteria/ archaea, small, no nucleus, no internal membrane system, cell wall of peptidoglycan
Eukaryotic: plant, animal, fungi, protist; large, has nucleus and internal membrane system
Similarities: outer plasma membrane, cytoplasm, ribosomes
What is the structure and function of ribosomes?
Function: synthesize proteins
Structure: no membrane bound, made of ribosomal proteins and rRNA, assembled in nucleolus
What is the structure and function of the mitochondria?
Structure: double lipid bilayer membrane (outer covers entire outside, inside is folded called cristae, the liquid center is the matrix)
Mitochondria only arise from pre existing mitochondria (endosymbiotic theory)
Function: energy metabolism (ATP production)
Describe the experiment used to discover the plasma membrane structure
counted RBC and calculated surface area. destroyed and collected membrane phospholipids. placed in chamber with buffer. measured total SA
What is the plasma membrane permeable too?
permeable: nonpolar molecules
less permeable: small polar
not permeable: large polar or ions
What are key characteristics of eukaryotic cell structure?
- internal compartmentalization
- membrane bound organelles and ribosomes are the exception
- different organelles perform different functions
What is the structure and function of the Endoplasmic Reticulum?
Structure: network of interconnected tubes, inside is called lumen
Function: Smooth: lipid, steroid, cholesterol, and carbohydrate; fatty acid desaturation
Rough: Protein synthesis for use in endomembrane system or destined to leave the cell
What is the structure and function of chloroplasts?
Structure: Double lipid bilayer (outer covers entire organelle, and within is thylakoid (disks), granum (stacks of disks), stroma (liquid substance) )
Function: site of photosynthesis
What was the findings of the experiment discovering the structure of the plasma membrane?
phospholipid bilayer (2:1 ratio)
movement of molecules across the membrane from high concentration to low concentration that does not require energy
Active transport (anti diffusion): movement of molecules from low concentration to high concentration; requires energy
As cell size increases, cell volume (demand) increases faster than cell surface area (supply)
What is the structure and function of the Golgi Apparatus?
Structure: flattened tubes (sacs), cis face- receives transport vesicles; trans face- transport vesicles exit
Function: proteins and other molecules may be modified, molecules are sorted by eventual destination, molecules are released in vesicles
What is the structure and function of the cytoskeleton?
Structure: network of multiple proteins inside a cell
Function: provides structural support inside the cell, role of transport in cells, and helps mobile cells move
What is the plasma membrane?
a selective barrier that defines the inside and outside of a cell
What is a channel protein? What is a carrier protein?
Channel: tunnel, do not bind to molecule being transported, always open or gated (open and closed), no energy
Carrier: bind to molecule being transported, no energy, 3 types:
uniporters (transport only one type of molecule), symporters (2 types of molecules same direction and time) antiporters (2 molecules different direction but same time)