FoB Lecture 6

what is the cell membrane?

phospholipid bilayer, surrounds the fluids and other structures that make up the “insides” of a cell

what is the cytoplasm?

the insides, which consists of water based cytosol contain dissolved molecules

what is a ribosome? what is the other name for it

RNA machines for making cell proteins ; rRNA

what is the cytoskeleton?

supports and maintains cell shape

railraod track for organelle and vesicle movement (motor proteins)

anchors cell and organelles make up cilia and flagella

• long spindle like fibers

what is a lysosomes? what is important about them?

breaks down unwanted substances like bacteria and worn out organelles

acidic (low pH) enviornment

what is a peroxisomes?

detoxify cells of lipids and alcohols

what is the nucleus? nucleolus?

nucleus: contains the genetic information (DNA) of the cell; RNA copies of protein-making information are made in the nucleus mRNA

nucleolus: where ribosomes rRNA are made

what regulates the movement of substances in and out of the nucleus?

nuclear pores

what is the continuous membrane with the nucleus?

endoplasmic reticulum

what does the smooth ER do?

lipid synthesis and lipid modification

what does the rough ER do?

protein synthesis by ribosomes attached to the plasma membrane

protein folding and quality control

protein glycosylation

what does the golgi apparatus do?

modifies, sorts, and packages the proteins and lipids from the ER

what is a vesicle?

Move proteins and lipids back and forth between the ER, Golgi, and cell membrane

Pulled and directed by motors proteins that are guided by the cytoskeleton

Explain the steps of protein creation/endomembrane system?

• in the nucleus, DNA (protein making library) is stored + RNA copies of genes are made (copy of instructions)

• in the endoplasmic reticulum (ER), the proteins and lipids are synthesized, proteins are folded/checked

• in the golgi apparatus, proteins arrived on the cis side and are modified, packaged, and put into vesicles on the trans side to be sent to where they function

• vesicles take proteins to the extracellular membrane, to final destination of protein function, or vesicles mature into their own organelles

what cells have large central vacuoles?

plant and fungi

what is a central vacuole?

large fluid filled organelles

store ions and toxic compounds

structures - for plant cells (water enters via osmosis)

what are cell walls? whats special about plant cell walls?

structural support and protection

plant cell walls - cellulose fibers are embedded

what is a chloroplast? membranes?

site of photosynthesis in plants

3 plasma membranes

What is a mitochondria? membranes?

in eukaryotes - site of chemical reactions of cellular respirations that supply most of the cellular energy

2 membranes

what organelles have their own DNA?

mitochondria and chloroplasts