THE WORKING CELL

Unit 5

I. CELL TRANSPORT

A cell is defined as the smallest ______unit of life. In order to maintain __________,___________ must be moved into the cell and _________ must be transported out of the cell. In addition, some cells produce ____________ and other materials designated for export. All materials moving in and out of the cell must pass through the __________________, a _____________boundary found in ____ cells.

workinghomeostasis nutrients

wastes

hormones

Cell membrane Semi permeableall

Outsideof cell

Insideof cell(cytoplasm)

Cellmembrane

Proteins

Proteinchannel Lipid bilayer

Carbohydratechains

There are two basic mechanisms for transport of materials into and out of the cell:

A. Passive Transport (pgs. 183 – 187) Does not require _____. Movement of substances from a ______concentration to _______. There are three types of passive transport:

energy

higherlower

high

low

Weeee!!!

Diffusion

1. Diffusion – Due to the random movement of molecules in ______ or ________. Many substances move across the ______________ by diffusion, for example,________________.

liquidgas

cell membranePerfume, food coloring, farts

•diffusion clip

Facilitated Diffusion

2. Facilitated Diffusion – Diffusion of _________________ through a _________________. Protein channels provide larger openings for larger molecules like _________________.

Larger Molecules

Protein channel

Glucose, fructose, galactose

•Clip of Facilitated Diffusion

Facilitated Diffusion Cont.

In addition, due to the __________ fatty acid tails that make up most of the phospholipid bilayer, _____ molecules and _________utilize protein channels. This includes _________, which utilizes specialized protein channels known as __________.

Non-polar

Polarions

Na and K

aquaporins

Osmosis

3. Osmosis – Diffusion of water from a ______ water concentration to a __________ water concentration through a _____________ membrane. There are comparative terms used to describe the water versus solute concentration on either side of a membrane:

high

low

Semi- permeable

Tonicity

Hypertonic = _________________ solute; ___________________ water

Hypotonic = __________________ solute; ___________________ water– Water always moves from

___________________ → _________________________

Increased concentration of

Decreased concentration of

Decreased concentration of

Increased concentration of

hypotonic

hypertonic

Tonicity

Isotonic = Relative concentrations of _____________ and _____________ are ___________– There will be ________ net movement of water

if two solutions are isotonic

water solute

equal

no

Tonicity

Cell Pressure Controls

Cells must have a mechanism for counteracting the pressure osmosis can create, otherwise a cell could swell & burst or explode when it is placed in a ____________ environment.

Cell Wall - Rigid boundary found in ________________, ______________, and _______________ cells

Contractile Vacuole - Actively ___________ water out of cell in single-celled organisms without _____________________

Blood/Extracellular Fluid – Designed to be _______________ with cells

hypotonic

plants fungibacteria

pumps

Cell walls

isotonic

ACTIVE TRANSPORT

B. Active Transport – Requires energy in the form of _____ (pgs. 188 – 189)ATP

high

low

This is gonna

be hard

work!!

Protein Pumps

1. Protein Pumps – Energy-requiring process during which membrane proteins pump molecules across a membrane ___________________________from a _________ concentration to a _______concentration. An example is the sodium-potassium pump. Its purpose is to establish an ____________________ gradient in cells by pumping _______ sodium ions (______) out of the cell for every ______ potassium ions (_____) pumped into the cell. This slight _____charge inside the cell relative to the outside is very important for ____________________________ and___________________.

against a concentration gradient LOWHIGH

Electrochemical 32Na

K K +-

Muscle contractionNerve impulses

Endocytosis

2. Endocytosis – “__________________”. Larger substances

are moved into the cell from the exterior by extending____________, forming a _________ around the substance.

Examples include macrophages,

amoeba, etc.

Cell eating or sucking

the cell membrane

vesicle

Endocytosis

Exocytosis

3. Exocytosis – “_________________”. Export of molecules

from the inside of the cell to the exterior of the cell by a _______ fusing with the cell membrane. Mechanism used to release ________

from cells

Cell Pooping or spitting

vesicle

hormones

II. METABOLISM

There are countless numbers of chemical reactions occurring in every cell all the time. Virtually all of these reactions require the action of _____________, catalytic ___________________. A catalyst _________ a chemical reaction without being _____________________. An enzyme works by lowering the activation energy, that is the energy required to ____________________.

enzymes proteinSpeeds up

Used up in the reaction

Get the reaction going

Enzymes share four common features:

A. Enzymes work best within a narrow _______ and ______________ range. This is because of the importance of the ______________ or ________________________ of the enzyme. When the pH or temperature is altered, the

_________________________ and interactions are also changed, changing the shape of the enzyme.

B. Enzymes do not make a reaction happen that couldn’t happen on its own; they simply make the reaction occur much __________.

pH

temperatureshape

conformation

Chemical bonds

faster

C. Enzymes are not _________________________. The same enzyme may be used over and over again.

D. Enzymes are _____________________________. The substrate is the ________________________. The substrate fits into a portion of the enzyme called the _______________________. As the substrate fills the active site, this leads to a phenomenon known as _____________________________, almost like a ___________. It is this induced fit that is responsible for lowering the ________________________ of the reaction.

used up in the reaction

substrate-specificreactant

active site

Induced fit Squeeze

activation energy

ENZYMES

III. CHEMICAL ENERGY AND LIFE (pp. 201, 202)

A. Energy and Life Energy is the ______________________. Cells require

energy for _________________ reactions, ________________transport, cell ____________________, and maintaining __________________. We obtain energy from _______________, but most energy originally comes from the ________. Plants are able to capture the sun’s energy and use it to produce glucose, ____________. This process, known as _________________, occurs in the ___________________ of plant cells. The reaction for photosynthesis is:________________________________________

ability to do workmetabolic

active divisionhomeostasis

foodsun

C6H12O6photosynthesis

chloroplasts

CO2 + H2O + energy C6H12O6 + O2

Energy and Life

Plants and other organisms that can make their own food are known as ________________________. Humans and other organisms that have to obtain food are known as _____________________________. Although glucose is the preferred energy molecule for the cell, other _________________________, ___________, and __________ can also be broken down for energy.

autotrophs

heterotrophs

carbohydrates lipids

proteins

B. Chemical Energy

The chemical energy in food (and all molecules) is stored in the ____________________________. This is ___________________________ energy. When the bonds are broken and the ___________________ are released, some energy is lost as ___________, but a percentage of the potential energy can be converted to useable energy in the form of ____________. Food molecules cannot be used as a direct energy source for the cell because food contains too much energy ... if it were released all at once, it would be _______________ and ___________________.

Chemical bondspotential

electrons

heat

ATP

wastefuldestructive

C. ATP

__________________________________ is a ________________________ that is composed of:

___________________ - nitrogen base ___________________ - _______ carbon sugar ______________________ Energy is stored in

______________________________________. These “rechargeable batteries” are mostly present in the cell in two forms:

Adenosine TriPhosphatenucleotide

AdenineRibose 5Three Phosphate Groups

Phosphate-phosphate bonds

ATP

ATP - ____________________________________. Has ___ phosphate groups.

ADP - ____________________________________. Has ____ phosphate groups.

________ has the most phosphate bonds, and therefore contains the most _______________ or stored energy.

Adenosine Triphosphate3

Adenosine Diphosphate2

ATP

potential

Cells are able to use and recycle ATP by breaking off or adding a ______________ group.phosphate

ATP-ADP Cycle

1. Energy can be used when a ___________ bond is ____________.

________________________________________________________ 2. Energy is stored; that is, ATP is “recharged” by ____________ a

phosphate group to ___________.

________________________________________________________ *Under normal conditions, both of these processes are occurring

at the _____________ and ______________ in a cell*

phosphate broken

ATPADP + Padding

ADP

ADP + P ATP

Same time All the time

IV. CELLULAR RESPIRATION - ___________ ENERGY PRODUCTION (pp. 221-223, 226-229)

Cellular respiration is the breakdown of _______________________ in the presence of _________________ to “make”___________. The oxygen required for cellular respiration is ___________ into the _________, __________ into the ____________, and is delivered to the __________________ of the body cells by ________________. The glucose needed is obtained through ____________________. The glucose is transported in the blood and enters the body cells via __________________________.

AEROBIC

glucoseOxygen O2 ATP

inhaled lungs diffusesblood

mitochondriaRed blood cells

digestion

Facilitated diffusion and protein channels

There are two major parts to cellular respiration:

A. Glycolysis – Means __________________________. Occurs in the ____________________ of the cell. Glycolysis does not require ___________________. The splitting of glucose, or glycolysis, occurs very quickly with the aid of _____________________, producing two _______-C molecules known as _________________________. In addition, when the bonds of glucose are broken, the high energy electrons that are released are caught by ____________, a molecule that acts as an electron carrier. This electron energy will be converted to ATP later in the

process. Glycolysis requires __________ ATP to occur, but results in the formation of _________ ATP, for a net ________________ of ________ ATP.

Reaction:

_______________________________________________________________ Net Energy Gain = _____________________

“Sugar-breaking”cytosoloxygen

enzymes 3Pyruvic acid

NADH

24 gain 2

C6H12O6 + 2ATP 2 pyruvic acid + 4ATP + 2NADH

2ATP + 2 NADH

Oxidative Respiration

B. Oxidative Respiration – Glycolysis releases less than ¼ of the chemical energy stored in glucose. Most of its potential energy remains bound in the _________________ formed from glycolysis. In aerobic conditions, meaning ____ is available, the pyruvic acid formed from the breakdown of ___________________ during ______________________ enters the ______________________________ of the cell where the __________________ of oxidative respiration complete the breakdown of glucose to produce _________, _________, and __________.

Reaction: __________________________________________________

pyruvic acidO2

glucose glycolysismitochondria

enzymesCO2

H2O ATP

2 pyruvic acid + O2 CO2 + H2O + ATP

Oxidative respiration is a 2-part process:

1. Krebs Cycle – Series of reactions that occur in the _______________________, in which the energy stored in ________________ is released in the form of high-energy ________________ when bonds are broken and pyruvic acid is completely broken down to ________. There are only ______ additional ATP produced in the Krebs Cycle; most of the energy released is captured in the form of electron energy, producing additional __________. In addition, a second type of electron carrier is utilized, producing 2 “filled” ____________.

Net Energy Gain = __________________________________________________

mitochondriapyruvic acidelectrons

CO2 2

NADHFADH2

2 ATP + 8NADH + 2 FADH2

Electron Transport Chain

2. Electron Transport Chain – In this step, the electron carriers, ___________ and ___________ “dump” their electrons. These electrons are passed along a series of molecules embedded in the inner membrane of the ___________________ of _______________ cells. This same process occurs in the __________________ of __________________ cells. As the electrons “fall” down the ETC, the energy they release is used to power an enzyme known as _____________________, which attaches phosphate groups to _________ to produce _________. This process is known as _________________________________because__________________ must be present. It is the __________________ of oxygen that “pulls” the electrons down the ETC. As the electrons are collected by oxygen, ___________ is produced.

Net Energy Gain = ___________________

NADH FADH2

mitochondria eukaryoticcell membrane prokaryotic

ATP synthaseADP ATP

Oxadaitive phosphorylation oxygenelectronegativity

water

~ 32 ATP

Mitochondrion

ETC

Combined Reactions of Glycolysis + Oxidative Respiration (Krebs &ETC) = Cellular Respiration*

__________________________________________________________*Total ATP Yield Per Molecule of Glucose:*

Glycolysis = _________ ATPKrebs Cycle = _________ ATP ETC = _________ ATP

C6H12O6 + O2 CO2 + H20 + ~ 32 ATP

22

28

V. FERMENTATION - _______________________ ENERGY PRODUCTION (pp. 223, 224)

Glycolysis is constantly occurring in the _____________ of every cell under _________________ conditions, meaning ___________________ is not required. The reaction for glycolysis is _____________________________

Glycolysis is the first step for all cellular energy production

ANEROBIC

cytosol

anerobicoxygen

C6H12O6 2 pyruvic acid + 2 ATP + 2 NADH

Glycolysis

Oxygen Available

If oxygen is available, _________________________________ follows glycolysis. Pyruvic acid is broken down to ______________ and _______ ATP are produced.

Oxidative respiration

CO2 + H2O 32

Oxygen is not Available

If oxygen is not available, some types of cells have a back-up mechanism for glucose metabolism called ______________________. If a cell cannot switch to fermentation, it cannot survive without oxygen.

– Cells that can carry out cellular respiration and fermentation are known as _______________________.

– Cells that cannot switch to fermentation are known as _______________________.

fermentation

Facultative anaerobes

Obligate aerobes

A. General Description

In fermentation, the pyruvic acid formed during glycolysis does not enter the ________________, instead, the entire pathway takes place in the ________________. Fermentation does not produce any additional _____________, but the removal of ________________ from the cytosol allows the process of glycolysis and the net gain of _______ ATP to continue.

mitochondria

cytosolATP

pyruvic acid

2

B. Types of Fermentation

The 2 most common fermentation pathways used by cells are:

1. Lactic Acid Fermentation – Pyruvic acid is converted to __________.

May be utilized by:

Lactic Acid

Fermentation

Human Muscle Cells – Occurs when demand on muscles exceeds supply of oxygen. As lactic acid builds up in the muscle cells, it is felt as ______________________. This is referred to as ________________. As activity slows, and oxygen is re-supplied, the muscle cells switch back to _______________________ and the lactic acid is sent to the ________to be broken down.

Bacteria & Fungi – There are some types of bacteria & fungi that carry out lactic acid fermentation in _______________________ conditions. This is utilized by the dairy industry to produce ___________ and _____________.

Pain and fatigueOxygen debt

Cellular respirationliver

anaerobiccheese yogurt

Alcoholic Fermentation

2. Alcoholic Fermentation – Pyruvic acid is converted to _________ and _________. When oxygen supplies are depleted, ____________ and many bacteria switch to alcoholic fermentation. This process is used commercially for ____________________________ ____________________________________

alcohol CO2

yeast

Brewing and bakingC6H12O6 2 pyruvic acid + 2 ATP

**TOTAL ATP GAIN IN FERMENTATION = ________ ATP **2