Ap bio Membrane structure function cell reproduction organelles
What kind of molecule is a phospholipid?
An amphipathic molecule meaning it has a hydrophobic region and hyrdopphilic.
What's the fluid mosaic model?
The membrane is a fluid structure wirh varioys proteins embedded in or attached to a double layer of phospholipids.
Davson danielli model
Sandwhiched phoshoplipid bilayer betweenb two protein layers. WRONG
Current fluid mosaic model
Disperses the proteins and immerses them in the phospholipid bi layer, which is in a flid state.
The core of the membrane is hydrophobic. True or false
Most lipids and some proteins can drift laterally
True rarely across center. Flip flopping
What are integral proteins?
Proteins that penetrate the hyrdophobic core of the lipud bilayer.
Not embedded in the lipid bilayer at all they are appendages loosely bound to the surface of the membrane
Cells ability to distinguish one type of neifhboring cell from another, is crucial to the functioning of an organism
Hyrdophilic substances avoid contact with the Lipid bilayer
By passing through transport proteins.
The tendency for
Molecules of any substance to spread out into available space
Function of membrane proteins.
Transport, enzymatic activity, signal transduction, inter cellular joining, cell-cell recognition, and attachment to the cytoskeleton and extracellular matrix.
Membrane carbs are important for cell cell recognition.
Short chains of sugars are linked to proteins and lipids on the exterior side of the plasma membrane, where they can interact with the surface molecules of other cells.
Passive transport is
Diffusion across a membrane.
Cell survival depends on balancing water uptake and loss.
A transport protein speeds the movement of water or a solute across membrane down its concentration gradient.
The pumping of of solutes against their gradients. Specific membrane proteins use energy,usually in the form of ATP, to do this work.
Exocytosis and endocytosis used to _____
Transport large molecules. in exocytosis- transport vesicles migrate to the plasma membrane, fuse with it, and release its contents. Endocytosis-large molecules enter cells. Phagocytosis, pinocytosis, receptor- mediated endocytosis
Cell division functions in reproduction, growth, and repair.
unicellular organisms reproduce by cell division. Multicellular organisms depend on it for development from a fertilized egg, growth, and repair.