Lecture 3&4- Cell Structure & Function Flashcards
What is the typical size range of Eukaryotic cells?
10-100 μm
What a the typical prokaryotic cell size?
1-10 μm
Why do cells come in various shapes and sizes?
They vary by their function Larger= has a higher function usually
What is the function of smooth muscle cells?
Contraction and shortening
What are the distinguishing organelles of plant cells vs animal cells?
Large central vacuole Chloroplasts Centriole (only found in animal cells)
What is the major component of cell walls?
Cellulose
What are integral proteins?
Proteins that span the whole membrane, usually function as channel or carrier proteins and gives the cell structure
What are peripheral proteins?
Proteins that do NOT span whole membrane, usually attached to integral proteins Can act as enzymes or help in cell signaling
What are the roles of carbohydrates in the bilayer?
Have a role in immune reactions (blood type antigen) Act as receptors for chemical pathways
In which process are macromolecules brought into the cell?
Endocytosis: Phagocytosis (solid) Pinocytosis (liquids) Receptor mediated Endocytosis- type of pinocytosis in which large molecules first bind to a receptor and are then engulfed (Specific)
What is a pseudopod?
an arm like structure that helps a cell undergo phagocytosis
Is the cytoplasm homogenous?
no, the centrosome, microtubules etc (cytoskeleton) , are involved
Why are the mitochondria able to replicate independently of the cell?
They have their own DNA
Where does the expired O2 from plants come from?
Catabolism of H2O
What is chemiosmosis?
Generation of ATP from the movement of H+ back across the inner mitochondrial membrane to the matrix
Define Hypotonic
solution that has a solute concentration lower than plasma ( lower osmotic pressure)
in Humans, that is having salt conc of less than 280osmol/L
What is the approximate solute conc in plasma?
280milliosmol/L
What is pinocytosis?
A type of endocytosis involving liquids or small particles
Mitochondrial diagram
Where are the carbohydrate chains attached in the bilayer in comparison to cytoskeleton fragments?
Carbohydrate chains towards the outside of the cell, cytoskeleton fragments towards the inside of the cell
Define diffusion?
the random motion of particles due to their thermal energy
particles tend to move from high concentration to low concentration
does not require membrane
Describe Oxidative phosphorylation in the mitochondria
- NADH & FADH2 are é donors
- there are more H+in inner mitochondrial membrane compared to matrix
NADH & FADH2 donate their high speed é to protein complexes
- as é lose energy protein complexes use it to take H+ to inner mitochondrial membrane against concentration gradient
- 3 H+ at a time (required to make 1 ATP)
- H+ move back to matrix via ATP synthase (3 at a time)
- ATP synthase uses the protons thermal energy to convert ADP->ATP
- O2 accepts low energy electrons+ 2H+ to form H2O
What is the thylakoid?
a stack of flattened sacs containing chlorophyll (inside the chloroplast)
What is the job of the thylakoid?
convert NADP+ and ADP –> ATP and NADPH
- light energy (photons) excite é to leave H2O, forming 2H+ & O2
- O2 leaves chloroplast while H+ are used to convert NADP+–>NADPH
- high speed electrons moving in thylakoid give enough thermal energy ADP->ATP
What happens after the thylakoid gets involved in chloroplast?
ATP and NADPH are used in the middle of the Calvin cycle (first starting with CO2) to convert it ultimately into sugar (series of reactions)
What is the analog of the matrix in the chloroplast?
Stroma
What is the function of a gland cell?
Production/ Secretion of substances.
What is the role of the cytoskeleton
Allows movement of organelles such as Mitochondria and components during exocytosis
