Unit 5 Cellular Energy

I. Enzymes (159) 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 proteins Speeds 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. pHtemperature shape conformation Chemical bonds

B. Enzymes do not make a reaction happen that couldn’t happen on its own; they simply make the reaction occur much _________. C. Enzymes are not ________________. The same enzyme may be used over and over again. faster Used up in the reaction

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. Substrate-specific reactant Active site Induced fit squeeze Activation energy

Metabolism ( ) All chemical reactions in a cell are referred to as cell ______________ Metabolic pathways- series of chemical reactions in which the __________of one reaction is the ___________for the next reactions. metabolism product reactant

2 Types: 2 Types: A. Catabolic pathways- _____________by breaking down larger molecules into smaller molecules EX. Cellular Respiration- ______ molecules broken down to release _______ for cell to use. B. Anabolic pathways- use the energy released by catabolic pathways ______________molecules from ______________ molecules. ◦ EX. Photosynthesis- ______________from Sun is ______________ to ______________in form of glucose. ◦ The relationship of anabolic & catabolic pathways results in the ________________________within an organism as well as within an ecosystem. Release energy organic energy To build larger smaller Light energy convertedChemical energy Continual flow of energy

III. CHEMICAL ENERGY AND LIFE (pp ) A. Energy and Life Energy is the ___________________. Cells require energy for ________ reactions, _____ transport,________, and maintaining ___________. We obtain energy from _____, but most energy originally comes from the sun. 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. Ability to do work metabolic active Cell division homeostasis food C 6 H 12 O 6 photosynthesis chloroplasts

The reaction for photosynthesis is: ______+______+__________________+_____ CO 2 H2OH2O Energy C 6 H 12 O 6 O2O2

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 bonds potential electrons heat wasteful ATP destructive

C. ATP C. ATP ___________________is a __________ that is composed of: ___________ - nitrogen base ___________ - 5 carbon sugar ___________________Groups adenine ribose 3 phosphate Adenosine TriPhosphate nucleotide

Energy is stored in __________________________. These “rechargeable batteries” are mostly present in the cell in two forms: ATP - Adenosine Triphosphate. Has 3 phosphate groups. ADP - Adenosine Diphosphate. Has 2 phosphate groups. Phosphate-phosphate bonds

_____ has the most phosphate bonds, and therefore contains the most ________ or stored energy. Cells are able to use and recycle ATP by breaking off or adding a _________ group. ATP potential phosphate

1. Energy can be used when a ________ bond is _________. _________________ 2. Energy is stored; that is, ATP is “recharged” by adding a phosphate group to ADP + P → ATP *Under normal conditions, both of these processes are occurring at the same time and all the time in a cell* phosphate broken ATP  ADP + P

REACTIONS of PHOTOSYNTHESIS Unit 4

Research into PHOTOSYNTHESIS began centuries ago with this simple question: When a tiny seed grows into a huge plant, where does all the “new plant” come from? CO2 and H20

THE BIG PICTURE Scientists discovered that in the presence of _________, plants transform CO 2 and water into carbohydrates and release oxygen. _____________ + ____________ _______________ + ____________ Carbon dioxide WATERSugars Oxygen 6 CO 2 _____________ + ____________ _______________ + ____________ 6 H 2 OC 6 H 12 O 6 6 O 2 → sunlight

PHOTOSYNTHESIS: Reactants & Products LIGHT ENERGY 6CO 2 + 6H 2 OSUGAR + 6O 2

In addition to water and, __________________ and __________________ are needed for photosynthesis to happen. chlorophyll light energy Carbon dioxide

Chloroplast Found mainly in the _______ of most plants Disk-shaped organelles contain 2 main compartments ◦ Thylakoids- flattened ____________________ that are arranged in stacks, this is where the light-dependent rxn take place here. ◦ Grana- stacks of ____________ ◦ Stroma- __________________ that is outside the _______, this is where light-independent rxn takes place leaves saclike membranes thylakoids Fluid-filled spaces grana

Pigments- light ___________colored molecules Found in __________ membranes Different pigments absorb specific _____________ of light ___________- ______most strongly in the ____________ region of the visible light spectrum & __________ light in the ______ region of the spectrum. (Why leaves appears green to our eyes) More abundant than other pigments in leaves, thus hides the colors of the other pigments. Different types called __________________ absorbing thylakoid wavelengths Chlorophyll absorb Violet-blue reflect green Chlorophyll a & b

Accessory pigments- allows plant to _______ different __________ of light energy  ______________- _________in _______________region &________, __________________________ Ex. β – carotene  In fall production of ____________________slows down or stops, thus bringing out the colors of the accessory pigments. absorb wavelengths Carotenoids absorb Blue & green reflect Yellow, orange & red chlorophyll

Visible light is made up of many different _______________of light Your eyes “see” different sizes of waves as different ___________ wavelengths colors

BUT… We “see” reflected light Light wavelengths that are ___________ off of objects bounce back to our eyes. That is the ___________ we “see” Image modified from: REFLECTED COLOR

ENERGY & ELECTRONS When chlorophyll absorbs light, the energy is transferred to electrons in the chlorophyll molecule. HIGH ENERGY ____________ make photosynthesis work! ELECTRONS

PHOTOSYNTHESIS HAPPENS IN CHLOROPLASTS Proteins that are part of the thylakoid membrane organize ________________________________ into clusters called _____________________ PHOTOSYSTEMS Light absorbing PIGMENTS

LIVING THINGS NEED ENERGY CARRIERS Molecule that carries = _______ Molecule that carries HIGH ENERGY ELECTRONS = ___________ ATP NADP + Images by Riedell

________ + _____ + _____ → ____________ NADP ____________ is one of the carriers that cells use to transport high energy electrons. NADP + 2 e - H+H+ Frying pan image from: BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006

LIGHT DEPENDENT REACTION Requires ______________ Molecules are part of ________________ Made up of __________________ connected by ______________________ & ___________________ Uses light energy to change ADP + P → _______ NADP + + 2e - + H + → _________ Breaks apart ______ molecules and releases _____________ LIGHT ATP THYLAKOID membranes PHOTOSYSTEMS II & I ELECTRON TRANSPORT CHAIN NADPH H20H20 oxygen ATP SYNTHASE

LIGHT-DEPENDENT REACTIONS See an animation about the ELECTRON TRANSPORT CHAIN Pearson Education Inc; Publishing as Pearson Prentice Hall SEE A MOVIE ATP SYNTHASE IN ACTION

CALVIN CYCLE (also called _________________________) ____________ require ____________ Happens in _________ between thylakoids NADPH donates _______________ ATP donates _________________ CO 2 donates ______________ to make __________ LIGHT LIGHT INDEPENDENT ENERGY STROMA Hydrogen + electrons Carbon & oxygen GLUCOSE DOES NOT

CO 2 Enters the Cycle Energy Input 5-Carbon Molecules Regenerated Sugars and other compounds 6-Carbon Sugar Produced Calvin Cycle See Calvin cycle animation

PHOTOSYNTHESIS OVERVIEW Pearson Education Inc; Publishing as Prentice Hall

Factors that Affect Photosynthesis ____________________ Water is one of the raw materials needed, so A shortage of water can ________________ photosynthesis AMOUNT OF WATER Desert plants and conifers that live in dry conditions have a waxy coating on their leaves to prevent water loss. slow or stop

Factors that Affect Photosynthesis Photosynthesis enzymes function best between 0° C - 35° C At temperatures above or below this range, photosynthesis will slow or stop Conifers in winter may carry out photosynthesis only occasionally TEMPERATURE

Factors that Affect Photosynthesis ____________________ More light increases rate of photosynthesis up to a certain level until plant reaches its maximum rate of photosynthesis LIGHT INTENSITY See effect of light experiment

THE BIG PICTURE PHOTOSYNTHESIS provides the _____________ we breathe and the __________ heterotrophs (like us) consume to survive _____________ + ____________ _______________ + ____________ Carbon dioxide WATER Sugars Oxygen OXYGEN sugars

Cellular Respiration Unit 5 Notes Continued

IV. CELLULAR RESPIRATION - ____________________________ ENERGY PRODUCTION 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 glucose oxygen ATP inhaled lungs diffuses blood mitochondria red 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 ______________. “ sugar breaking” cytosol oxygen enzymes 3 Pyruvic acid

Glycolysis 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 NAD+ two four gain two

Glycolysis Reaction: _______________________________ Net Energy Gain = _____________________ _ C 6 H 12 O ATP → 2 pyruvic acid + 4 ATP + 2 NADH 2 ATP + 2 NADH

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. Pyruvic acid

Oxidative Respiration 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: ________________________________ O2O2 glucose glycolysis mitochondria enzymes _ CO 2, H2O,H2O, ATP 2 pyruvic acid + O 2 → CO 2 + H 2 O + ATP

Site of Oxidative Respiration

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 = _______________________________________ mitochondria Pyruvic acid electrons CO 2 2 NADH FADH 2 2 ATP + 8 NADH + 2 FADH 2

Krebs Cycle

Electron Transport Chain

2. 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 ____. NADH FADH 2 mitochondria Eukaryotic cell membrane prokaryotic ATP Synthase ADP ATP

Electron Transport Chain 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 = ________ oxidative phosphorylation oxygen electro negativity water ~ 32 ATP

Cellular Respirations

Combined Reactions of Glycolysis + Oxidative Respiration (Krebs &ETC) = Cellular Respiration* ___________________________ Total ATP Yield Per Molecule of Glucose: Glycolysis= ____ATP Krebs Cycle=____ATP ETC= ____ATP C 6 H 12 O 6 + O 2 → CO 2 + H 2 O + ~32 ATP

STAGEWHER E # ATP GLYCOYS IS CYTOPLA SM 2 KREBS CYCLE OUTER MITOCHOND RIA 2 ELECTRO N TRANSPO RT CHAIN INNER MITOCHOND RIA 32

V. FERMENTATION – _______________________ ENERGY PRODUCTION 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. ANAEROBIC CYTOSOL ANAEROBIC OXYGEN C 6 H 12 O 6 → 2 pyruvic acid + 2 ATP + 2 NADH

Fermentation If oxygen is available, ___________________ follows glycolysis. Pyruvic acid is broken down to __________ and ____ ATP are produced OXIDATIVE RESPIRATION CO 2 + H 2 O 32

Fermentation 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 CYTOSOL ATP 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 __________________. LACTIC ACID

May be utilized by: 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. PAIN AND FATIGUE OXYGEN DEBT CELLULAR RESPIRATION LIVER

May be utilized by: 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 ___________.  C 6 H 12 O 6 → 2 pyruvic acid + 2 ATP + 2 NADH → lactic acid ANAEROBIC CHEESE YOGURT

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 CO 2 YEAST BREWING AND BAKING

Alcoholic Fermentation

Fermentation Products

Alcoholic Fermentation ______________________________ **TOTAL ATP GAIN IN FERMENTATION = ________ ATP ** C 6 H 12 O 6 → 2 pyruvic acid + 2 ATP + 2 NADH → alcohol + CO 2