midterm 1 Flashcards
what can proteins do? (7 things)
speed up chemical reactions, defence, storage, transport, cellular communication, movement, and structural support
what is an enzyme?
enzymatic proteins that regulate metabolism acting as a catalyst ( speed up chemical reactions w/out being consumed by the reaction).
what are proteins constructed from?
the same 20 amino acids linked in unbranched polymers.
what is a peptide bond?
bond between amino acids.
what is the structure of an amino acid?
organic molecule with both an amino acid group and carboxyl group.
describe the flow of genetic info (DNA->RNA->Protein)
in notes 11 steps
what are ribosomes?
complexes made up of ribosomal RNA and protein that carry out protein synthesis.
are ribosomes organelles?
No, because aren’t membrane bound.
describe selective permeability.
acts a gatekeeper, some substances are allowed through the membrane while others aren’t. chemical exchanges allow for cell to discriminate.
characteristics of cellular membranes.
lipids proteins and carbs make it up. phospholipids are most common. temp affects the fluidity. double bonds cause unsaturated hydro carbon tails to move apart making membrane more fluid.
what is a fluidity buffer for the cellular membrane?
cholesterol, high temp makes less fluid restraining the phospholipid bi layer.
define amphipathic
hydrophobic and hydrophilic (phospholipids).
what are integral proteins?
the channels that penetrate the cellular membrane to form a channel to allow certain substances through.
what are peripheral proteins?
aren’t channels are only proteins on the outside attached. attached to the matrix and cytoskeleton.
what type of channel is the transport?
one spans through the membrane selectively choosing (hydrophilic). one side is a protein shuttle changing shape to fit what’s needed, use atp, some hydrolyze.
what type of transport is enzymatic activity?
two enzymes beside one another, one gathers a substance, changes the shape and moves it to the second enzyme where it changes again and moves on.
what type is signal transduction?
binding site with a specific shape at the top of a receptor molecule, signalling molecule attaches to the receptor and moves through (chemical messenger/hormone).
what type is cell-cell recognition?
glycoprotein serves as a recognition tag to a another cell membrane protein connect. (short lived).
what type is intercellular joining?
membrane proteins of adjacent cells may connect through gap/tight junctions. (long-lasting).
what type is attachment to the cytoskeleton and ECM?
elements of the cytoskeleton none covalently bond to the membrane proteins, maintains the shape, stabilize location of certain proteins.
what are the 7 characteristics of life?
order/organization, regulation, energy processing, growth, sense/response to changes, reproduction, evolutionary adaptation.
why are cells the most basic levels of organization?
smallest unit
characteristics of prokaryotic cells.
no organelles, no nucleus to hold DNA, small, have nucleoid.
what does plasmodesmata mean?
only in plant cells (eukaryotic), cytoplasm that travels between cell walls to allow cellular communication.
what makes up a phospholipid?
lipids= fats, h20 loving head and h20 hating tails, tails are 2 fatty acids.
one main function of microvilli?
increase SA which increases absorption
endomembrane system of the nucleus?
holds most genetic info in, biggest organelle, x2 membrane, nucleus pores->mRNA->to make protein, lamina=shape, matrix=fluid (chromosomes), function= synthesize and produce mRNA which code for polypeptide chains.
endomembrane system of the smooth ER.
connected to the nuclear membrane (1 system), proteins from nucleus folded and then moved from smooth to the golgi, lipids synthesize, carbs metabolism, detox of drugs (poisons), stores Ca+2
endomembrane system of the rough ER.
connected to the nuclear membrane, polypeptide chains moved from pores of nucleus into ER, make proteins certain shapes, use vesicles to transport, polypeptide chain made into proteins, membrane factory, pancreatic cells produce…
endomembrane system of the golgi apparatus.
storage of protein, cisternae are the folds, cis face= receiving side, trans face= shipping out side, vesicles from ER come here, vesicles ship out proteins to membrane or in cell to where needed.
endomembrane system of mitochondria.
production of ATP through cellular respiration, converts energy into different types for different cells, x2 membrane, folded cristae inside for >SA, re-produce or make less for the cell.