AP Bio Unit 2: Cell Structure and Function Flashcards
Genomes are encased in what?
They are encased in membrane-bound organelles called nuclei.
sing. nucleus
What reflects commom ancestry in eukaryotes and proaryotes?
Genomes and ribosomes
Are ribosomes membrane enclosed structures?
No
What are ribosomes made up of?
Two subunits (one big and one small), more in future lessons
What is needed to synthesize protiens using ribosomes?
mRNA, tRNA, and amino acids
Is the ER membrane enclosed?
Yes
What does the rough ER do?
It packages the newly synthesized protiens for transport out of the cell
What does the smooth ER do?
It’s functions include detoxification and lipid synthesis
What is the golgi complex made of?
Its a series of flattened membrane bound sacs (in eukaryotic cells)
What does the golgi complex do?
Its involved in the correct folding and modification of newly synthesized protiens and packaging for protien traffacking
What is a mitochondrion made of?
A smooth outer membrane and convuluted inner membrane called cristae
What does mitochodria do?
It functions in the production of ATP
What is a lysosome sac?
It’s a membrane enclosed sac filled with hydrolytic enzymes
What do lysosomes do?
Their enzymes can be used to digest damaged cell parts or macromolecules
What are vacuoles?
They are membrane bound sacs
What do vacuoles do?
Storage of water and release of waste in a cell (perhaps more things as well)
What are chloroplasts?
They’re structures that have double membranes and that are specialized in capturing energy from the sun and producing sugar for the organism
What are the two compartments that make up a chloroplast?
Thylakoids and stroma
What are thylakoids?
They are highly folded membrane compartments that are organized in stacks called grana.
What are some features of the thylakoids?
Its membranes contain chlorophyll, and electron transport protiens can be found between the photosystems, embedded in the thylakoid membrane. The light dependent reactions occur there.
What are some features of the stroma of chloroplasts?
It is the fluid between the inner chloroplast membrane and outer thylakoids, and it is where the carbon fixation cycle occurs.
What are photosystems and where are they located?
Photosystems are complexes of proteins and pigments found in the thylakoid membranes of chloroplasts in plant cells (and in the membranes of cyanobacteria.)
Where do the light independant reactions occur?
In the stroma of the chloroplasts in plant cells.
Also known as the Calvin cycle
Where do the light dependant reactions occur?
In the thylakoids of chloroplasts
Why is it better for cells to be small?
- Because the cell typically has a greater cell to surface area to volume ratio, which leads to a more effecient exchange of materials
- Transporting things such as waste and nutrients gets more challenging the bigger the cell is
Smaller cells that have greater surface area to volume ratios have…
- Better chances of survival
- Adequate surface area to channel the exchange of nutrients needed by the cell and waste expunged out of the cell
What’re the formulas for surface area and volume?
SA: 4pir^2
V: 4/3pir^3
What are some examples of membrane folding increasing surface area?
Root hairs on the surface of plant roots, and membrane folds on the lining of the small intestine (villi and microvilli)
What is one thing that gets affected in larger organisms (considering their smaller surface area to volume ratio)?
Their heat dissapation
How do elephants combat their smaller surface area to volume ratio?
Their ears to dissapate heat
What are stomata?
They are specialized exchange surfaces that change their shape in order to obtain or release certain molecules from or into the environment
What do cell membranes provide?
A barrier between the inside and outside of the cell
What do cell membranes control?
They control the transport of materials in and out of the cell
What are the protiens that can be found in the cells membrane?
Integral and periphiral protiens
What does amphipathic mean?
It’s a term used to describe something that’s both hydrophillic and hydrophobic
What do phospholipids form?
They spontaneously form a bi-layer in an aqeous environment
What is a phospholipid made of?
A hydrophobic phosphate head, which is polar, and a hydrophobic fatty acid tail, which is nonpolar.
Are protiens that are part of the cells membrane hydrophillic or hydrophobic?
Actually they can be either:
1. Periphiral protiens are hydrophillic.
2. Integral protiens are both hydrophillic and hydrophobic
What are some functions of the membrane protiens?
- Transport
- Cell-cell recognition
- Enzymatic activity
- Signal transduction
- Intercellular joining
- Attachment for intracellular matrix or cytoskeleton
What is the framework of the cell membrane described as?
A Fluid Mosaic Model
Are the bonds of the cell membrane weak or strong, and why?
It is relatively weaker than covalent bonds because it’s held together primarly by hydrophobic interactions
What is cholerstrol?
A type of steriod
What does cholerstrol do in the Fluid Mosaic model?
It is randomly distributed and wedged between phospholipids of eukaryotic cells and regulates bilayer fluidity under different conditions of the cell
What does a Fluid Mosaic Model contain?
A phospholipid bilayer, protiens (periphiral and integral). cholestrol, and carbohydrates
What do carbohydrates do in the fluid mosaic model?
They function as markers.
What are the different types of carbohydrate markers?
Glycoprotiens: attached to protiens
Glycolipids: attached to lipids
