Chapter 5 Biology

Front 1

Plasma Membrane

Back 1

8 nm thick

Front 2

Cholesterol Within the Animal Cell Membrane:

Back 2

Cholesterol reduces membrane fluidity at moderate temperatures by reducing phospholipid movement, but at low temperatures it hinders solidification by disrupting the regular packing of phospholipids.

Front 3

Integral Proteins

Back 3

Penetrate the hydrophobic core of the lipid bilayer. Many are transmembrane proteins, which completely span the membrane. The hydrophobic region of an integral protein consists of one or more stretches of nonpolar amino acids

Front 4

A phospholipid

Back 4

amphipathic molecule, meaning is has both a hydrophilic region and a hydrophobic region.

Front 5

Fluid Mosaic Model

Back 5

The membrane is a fluid structure with a “mosaic” of various proteins embedded in or attached to a double layer (bilayer) of phospholipids.

Front 6

Six Major Functions Performed by Proteins of the Plasma Membrane

Back 6

Transport

Enzymatic Activity

Signal Transduction

Cell-Cell Recognition

Intercellular Joining

Attachment to the Cytoskeleton and Extracellular Matrix (EXM)

Front 7

Mosaic

Back 7

small pieces

Front 8

HIV

Back 8

Can infect a cell that has CCR5 on its surface that is most people

Cannot affect a cell lacking CCR5 in resistant individual

Front 9

Passive Transport

Back 9

the diffusion of a substance across a membrane with no energy investment

Front 10

Diffusion

Back 10

tendency for molecules to spread out evenly into the available space along a concentration gradient

Front 11

Although each molecule in passive transport moves randomly

Back 11

diffusion of a population of molecules may be directional

Front 12

Dynamic equilibrium

Back 12

Many molecules cross the membrane in one direction

Front 13

Passive transport

Back 13

substance diffuse down their concentration gradient

Front 14

Concentration gradient

Back 14

change/difference in the concentration of solutes in a solution between regions

Front 15

No work must me done to move substances down the concentration gradient in passive transport

Back 15

N/A

Front 16

The diffusion of a substance across a biological membrane

Back 16

passive transport

Front 17

what factors can influence the rate diffusion

Back 17

N/A

Front 18

Osmosis

Back 18

the diffusion of water across a selectively permeable membrane

Front 19

water diffuses across a membrane from

Back 19

the region of lower solute concentration to the higher solute concentration until the solute concentration is equal on both sides.

Front 20

lower solute concentration

Back 20

hypotonic

Front 21

higher solute concentration

Back 21

hypertonic

Front 22

tonicity

Back 22

the ability of a surrounding solution to cause a cell to gain or lose water based on osmosis.. 3 types: Isotonic, Hypertonic, Hypotonic

Front 23

Isotonic Solution

Back 23

Solute Concentration is the same as the inside, not net water movement across the plasma membrane

Front 24

Hypertonic Solution

Back 24

Solute concentration is greater than that inside the cell; cell loses water

Front 25

Hypotonic Solution

Back 25

Solute concentration is less than the inside of cell, cell gains water

Front 26

Why doesn't the plant cells burst in a hypnotic solution

Back 26

N/A

Front 27

Plasmolysis

Back 27

is in a hypertonic environment where plant cells lose water and eventually the membrane pulls away from the wall..

Front 28

Passive transport

Back 28

Aided by protein

Front 29

Facilitated diffusion

Back 29

transport proteins speed the passive movement of molecules across the plasma membrane

Front 30

Channel protein

Back 30

provide corridors that allow a specific molecule or ion to cross the membrane

Front 31

Channel proteins include:

Back 31

Aquaprotein: for facilitated diffuse of water

Ion channels that open or close in response to a stimulus (gated channels)

Front 32

Active transport

Back 32

moves substances against their concentration gradients

Front 33

Active transport requires

Back 33

energy usually in the form of ATP

adenosine triphosphate

Front 34

Active transport s performed

Back 34

by a specific carrier proteins embedded in the membranes

Front 35

Active transport allows

Back 35

cells to maintain concentration gradients that differ from their surrounding

Front 36

Sodium-potassium pump

Back 36

type of active transport system and is involved in the conduction of nerve impulses

Front 37

bulk transport

Back 37

across the plasma membrane occurs by Exocytosis and Endocytosis

Front 38

Small molecules (oxygen and carbon dioxide) and water enter or leave the cell though the lipid bilayer or via transport proteins

Back 38

N/A

Front 39

Large molecules

Back 39

Polysaccharides and proteins cross the membrane in bulk via vesicles

Front 40

Bulk transport

Back 40

requires energy

Front 41

Exocytosis

Back 41

transport vesicles migrate to the membrane, fuse with it, and release the contents

Front 42

Exocytosis

Back 42

Secretory cells use it to export products

Front 43

Endocytosis

Back 43

the cell takes in macromolecules by forming vesicles from the plasma membrane

Front 44

Endocytosis

Back 44

is a several of exocytosis involving different proteins

Front 45

Two types of endocytosis

Back 45

Phagocytosis: cellular eating

Receptor-mediated endocytosis

Front 46

LDL

Back 46

low density lipoprotein and transports insoluble cholesterol

Front 47

Energy of Life: Living Cell

Back 47

Cell extracts energy and applies energy yo perform work

Front 48

Organism Metabolism

Back 48

transforms matter and energy subject to the laws of thermodynamics

Front 49

Metabolism

Back 49

the totality of an organisms chemical reaction

Front 50

Intermediary meatabolism

Back 50

the chemical reactions that occur in cell

Front 51

Metabolic pathways

Back 51

are virtually identical in all living cells

Front 52

Metabolic pathways

Back 52

begin with a specific molecule and end with a product. each steps catalyzed by a specific enzyme

Front 53

Forms of energy

Back 53

kinetic: motion

heat(thermal energy): random movement atoms

potential energy: matter have cause of location

chemical energy: potential energy available for release in a chemical reaction

Front 54

Energy

Back 54

can be converted from one another but not destroyed or lost

Front 55

Thermodynamics

Back 55

the study of energy transformation

Front 56

Closed system

Back 56

isolated: like liquid in a thermo is isolated from its surroundings

Front 57

open system

Back 57

energy and matter can be transferred between the system and its surrounding

Front 58

Are cells, organisms, the earth, universe open systems

Back 58

yes

Front 59

First law of thermodynamics

Back 59

the energy of the universe is constant

Front 60

the fist law is called

Back 60

principle of conservation of energy

Front 61

First law of thermodynamics

Back 61

energy changes form : chemical energy

Front 62

second law of thermodynamics

Back 62

during every energy transfer or transformation some energy is reusable and is often lost as heat

every energy transfer or transformation increases entropy (disorder of universe)

Front 63

second law of thermodynamics

Back 63

bear with co2