UNIT 3 CELL BOUNDARIES AND TRANSPORT Unit 3

UNIT 3 CELL BOUNDARIES AND TRANSPORT Unit 3 test: October 19/20

CELL BOUNDARIES Cell Wall protect support – _______ & _______ the cell membrane – Lies outside of the _________ carbohydrates – Is made of _______& proteins _______ – Plant cell walls are mainly ______ cellulose – Fungi cell walls are mainly ______ chitin

CELL BOUNDARIES • II. CELL Membrane working unit of • A cell is defined as the smallest _____ homeostasis _______ nutrients life. In order to maintain ______, must be moved into the cell and wastes ______ must be transported out of the cell. In addition, some hormones and other materials cells produce _____ designated for export. All materials moving in and out of the cell must pass through the semi permeable cell membrane _______boundary ______a found all cells. in ____

Cell Membrane in a Nutshell (187 -190) phospholipid & _____ proteins – Made mainly of ______ – Hydrophobic tails of phospholipids make molecules line up as a bilayer with polar head facing _______ out and nonpolar _____ in tails facing ___.

Function – Membranes are _________ selectively permeable = Semipermeable, picky – Allow certain molecules to pass through; but keeps others out – _____ Controls what enters & leaves the cell – Helps maintain homeostasis ______

Other components of the cell membrane – Proteins • Peripheral- on the inside or outside surface. Can be partially embedded into the cell membrane or can be found attached to an integral membrane protein. transmit signals to inside – On the outside surface, ______ cell; “receptor protein” anchors the call – On the inside surface, _____ membrane to the cell’s internal support structure (cytoskeleton) giving cell its shape. “Anchor proteins” – Transport proteins (also called integral)embedded all the way through the ____________ membrane; used as channels or tunnels to move things in or out of the cell

Other components of the cell membrane • Cholesterol- only in _______ animal cells –Helps prevent fatty acid tails from sticking together ____ stability for ____ animal –Provides ____ cell (no cell wall)

Other components of the cell membrane • Carbohydrates- in chain form; on outside surface recognize self ; cell ID tags –Used to ______ –If found on top of a protein the whole structure is called a _______ glycoprotein –If found on top of a phospholipid the glycolipid whole structure is called a _____

Label the following cell membrane 1. 2. 3. 4. 5. Transport/Integral Protein Peripheral Protein on the inside Glycoprotein Glycolipid Cholesterol

CARBOHYDRATES • On the outside of the cell membrane to identify as “self or non-self”

PROTEINS • Embedded in the bilayer • Serve as channels & pumps for transport of specific molecules across the cell membrane

What biomolecule regulates what can enter or leave the cell w/o a channel or pump? A. B. C. D. Lipid Carbohydrate Protein Nucleic Acid

What biomolecule Serve as channels & pumps for transport A. B. C. D. Lipid Carbohydrate Protein Nucleic Acid

What biomolecule is used to to identify as “self or non-self” A. B. C. D. Lipid Carbohydrate Protein Nucleic Acid

Non-polar, middle portion of cell membrane A. B. C. D. E. a b c d e

Embedded in cell membrane, serve as channels & pumps A. B. C. D. E. a b c d e

Polar portion of cell membrane oriented towards water A. B. C. D. E. a b c d e

Provides stability for animal cell membrane A. B. C. D. E. a b c d e

Serve as “id” tags for cell A. B. C. D. E. a b c d e

CELL TRANSPORT Passive Transport energy • Does NOT require ____ high • Movement of substances from a ______ low concentration to ______ • 3 Types: o Diffusion o Facilitated diffusion o Osmosis

DIFFUSION Diffusion: liquid • Random movement of molecules in a ____ gas or _____ Many substances move across cell membrane by the ________ diffusion, for example water, oxygen, & small molecules _____________ • Example: odor gradually fills a room

FACILITATED DIFFUSION Facilitated Diffusion: • Diffusion of _______through a large molecules protein channel _______ • Ex: glucose as it is transported across a cell membrane by a protein channel

FACILITATED DIFFUSION • Protein channels provide larger openings for larger molecules like glucose, & fructose In addition, due to ________. the _____ non-polar fatty acid tails that make up most of the phospholipid bilayer, polar molecules and _____ ions utilize _____ protein channels.

FACILITATED DIFFUSION Na & K which utilizes • This includes ____, specialized protein channels known as ________. Protein pumps ***A protein pump is active transport so this sentence should be in the active transport section

OSMOSIS Osmosis: • Diffusion of ____from a _______ water high water concentration to a ____ low water Selectively permeable concentration through a _________ membrane. There are comparative terms used to describe the water versus solute concentration on either side of the a membrane:

OSMOSIS • Hypertonic = _________solute; higher concentration lower concentration _________water lower concentration • Hypotonic = __________solute; higher concentration _________water hyp. Otonic – Water always moves from ______→ _______ hypertonic

OSMOSIS water • Isotonic = Relative concentrations of ______ equal and ______ solute are ____ no net movement of water if two – There will be ___ solutions are isotonic

OSMOSIS • Cells must have a mechanism for counteracting the pressure osmosis can create, otherwise a cell could swell & burst or explode when it is placed hypotonic environment in a ______ • How to control Osmotic Pressure: o Cell wall - Rigid boundary found in Plants, ________ bacteria, fungi & some protists o Physically prevents cell from expanding o Contractile vacuole- Actively____ pumps water out of cell single-celled organisms without Cell ____ walls o Blood/Extracellular Fluid- is mostly water to equalize osmotic pressure. Designed to be _____ isotonic with cells.

-Hypotonic; -cell will undergo cytolysis or lyse (the cell will burst) -This can kill the animal cell -Hypertonic; -isotonic; -cell will crenate (the cell -preferred cell state will shrivel up) -This causes cell to dehydrate and not function -Hypertonic; -cell will undergo plasmolysis (cell membrane pulls away from cell wall) -isotonic; -Cell does not mind being in this state; neither beneficial or harmful to the cell -Hypotonic; -cells see increased turgor pressure -This is the preferred state for plant cells

ACTIVE TRANSPORT Requires energy in the form of ATP 3 types: • Protein Pumps • Endocytosis • Exocytosis

PROTEIN PUMPS Protein Pumps: • 1. Protein Pumps – Energy-requiring process during which membrane proteins pump molecules across a membrane gradient concentration __________ from a ______ low concentration to a high ____concentration.

PROTEIN PUMPS An example is the sodium-potassium pump. Its purpose is to establish an electrochemical _______ gradient in cells by pumping __ 3 sodium ions (__) Na 2 potassium ions (__) out of the cell for every __ K negative pumped into the cell. This slight ____ charge inside the cell relative to the outside is contractions very important for muscle ________ Nerve impulses and _________.

ENDOCYTOSIS AND EXOCYTOSIS Endocytosis: “cell eating or sucking”. Larger substances are moved into the cell from the exterior by extending the cell membrane, forming a vesicle around the substance. Examples include macrophages, amoeba, etc. Exocytosis- “cell spitting ”. Export of molecules from the inside of the cell to the exterior of the cell by a vesicle fusing with the cell membrane. Mechanism used to release hormones from cells

ENDOCYTOSIS AND EXOCYTOSIS

ENDOCYTOSIS

Endocytosis

Exocytosis

Random movement of molecules in a liquid or gas A. B. C. D. E. F. G. H. Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump

Requires energy in the form of ATP A. B. C. D. E. F. G. H. Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump

cell sucking in or eating A. B. C. D. E. F. G. H. Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump

Diffusion of specific molecules through a protein channel A. B. C. D. E. F. G. H. Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump

Diffusion of water through a selectively permeable membrane A. B. C. D. E. F. G. H. Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump

A. B. C. D. E. F. G. H. Movement of molecules from high concentration to low, does NOT require energy Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump

A. B. C. D. E. F. G. H. Movement of ions and molecules against the concentration gradient, requires energy Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump

Cell spitting out or pooping A. B. C. D. E. F. G. H. Active transport Diffusion Endocytosis Exocytosis Facilitated Diffusion Osmosis Passive Transport Protein Pump