Enzyme Review

Enzyme ReviewAre you ready?

Define Catalyst.A molecule that allows stable molecules to react quickly.

What is an enzyme?

and what is it made of?

An enzyme is a biological catalyst

It is a protein and made of a

long chain of amino acids

What do enzymes do?They speed up chemical reactions by…….

Lowering Activation Energy needed to start the reaction.

What enzyme did we use in our labs?

Catalase

What reaction does it speed up?

The breakdown of Hydrogen Peroxide into water and oxygen.

H2O2--------) H2O + O2

Why are enzymes necessary?

So that chemical reactions in living things can happen fast enough

Example- In the human body—

Hydrogen Peroxide would break down without catalase, but it would be so slow that H2O2 would build up and become TOXIC!

Name the two kinds of reactions.

Exothermic Endothermic

Which requires energy input

and which gives off heat?

Endothermic RXNS require energy to be

added IN to keep going.

Exothermic RXNS give off energy. Energy

EXITS.

What does it mean to say a reaction is “spontaneous”?

Once it starts it will continue until the end.

No energy input is required after the activation energy.

Define Activation Energy.

The measure of how hard molecules have to collide to get a reaction to begin.

The push to get a reaction started.

Which kind of molecules have high activation energy—Stable or Unstable?

Stable molecules don’t interact easily– they have HIGH activation energy. Need a bigger push to get started.

Unstable molecules react more easily--They are highly reactive, have LOW activation energy.

What is KMT?

Kinetic Molecular Theory

The idea that molecules are always moving and when they collide hard enough with one another, they will react.

What happens when enzymes are exposed

to heat?A little heat can speed up a reaction by

making the molecules move faster----

BUT

What happens when there is too much

heat or the wrong pH?Enzymes DENATURE

They unravel. They no longer keep the same shape so they won’t fit the substrate any more.

They need to be in their OPTIMUM range of temp or pH to function the best!

Explain Lock and Key Model

Enzyme is the

Lock

Substrate is the

Key

The active site is the

Keyhole

What happens at the active site?

The enzyme and the substrate bind together.

What is Induced Fit?

Amino acids in the active site

Attract amino acids on the substrate due to different charges and polarity

They interact and the bonds are broken and new ones form.

Can an enzyme be used in any reaction?

NO

They are very SPECIFIC, SELECTIVE, PICKY

They only work with one substrate.

Are enzymes used up in a reaction?

NO

They can be used over and over again.

What happens when you add more enzyme?

The rate of reaction increases– Happens faster

What happens when you add more substrate?

No change in rate, BUT

You get more product.

Thanks for playing

Enzyme Review

Biochemistry ReviewBiology is the study of living things.

Organic or Biochemistry is the study of the chemical reactions in living things.

What is the smallest unit of matter?

An Atom

Atoms- What area is positive and what area is

negative?The nucleus is positive

The surrounding electron orbitals are negative

Where is the mass?

In the nucleus

Atoms Atomic Number= # of p+

Atomic Mass= p+ + n0

Charge= p+ - e-

First Energy Level= can hold ..

2 electrons

Second Energy level can hold..

8 Electrons

What is a molecule?Atoms bonded together with covalent bonds

How are ions and isotopes same/different?

They are both atoms and the number of protons stays the same, BUT

Ions have different charges (different number of electrons)

Isotopes have different masses (different number of neutrons)

What makes a molecule polar?

Uneven sharing of electrons gives the molecule partially negative areas and partially positive areas

Give an example of a polar molecule.

Water – H20= Oxygen has a partial negative charge, hydrogen has a partial positive charge.

What is a compound?

A substance made of two or more different elements.

Could be bonded by ionic or covalent bonds

What is the most common element in living things?

CarbonIt is present in all four of the biomolecules

Which biomolecule contains nitrogen?

Protein

Let’s talk about bonds!

What are the three types we have covered?

Ionic, Covalent, and Hydrogen bonds

A Bond formed when molecules share

electrons

Covalent Bonds

A Bond between two oppositely charged atoms or molecules (one positive one

negative)Ionic bonds

An intermolecular force between polar

moleculesA Hydrogen Bond

What is the relative strength of these

bonds?

Covalent/ Ionic >>>>>>>Hydrogen Bonds

pH scale 1-14What does it measure?

The acidity or basicity of a solution

7 is neutral

Acids are …

Below 7

Bases are …

Above 7

Four Categories of Biomolecules

Proteins

Carbohydrates

Lipids

Nucleic Acids

These are very large molecules so we call them Macromolecules!

Carbohydrates- What do we know?

Ratio of C:H:O is

1:2:1

Monomers are:

saccharides-simple sugars

Polymers are:

polysaccharides- starches

LipidsMonomers are glycerol and fatty acids

Polymers are Trigycerides- a glycerol with three fatty acid chains

Lipids can be fats or oils,

They are nonpolar- don’t mix with water

Saturated fats are solid (butter, lard)

Unsaturated are oils (olive, vegetable)

ProteinsMonomer is an amino acid (20 types), each amino acid has an R group on its central carbon.

Polymers are polypeptides, two or more amino acids bonded together

What is the process that builds polymers

from monomers?Dehydration Synthesis (synthesize is to make)

Remember this process gives off a molecule of ……

H20

Breaking down polymers into

monomers is called

Hydrolysis- “Lysis” is to break

What molecule is needed for this to happen?

H20 must be present and breaks into its parts to replace the H’s and O

In our lab, we tested for different biomolecules:

Iodine- What does it test for and what’s a positive reaction?

Iodine tests for starch- If starch is present it turns..

Blue-Black

What tests for simple sugars (Glucose)?

Benedicts plus heat (it starts out blue)

Positive reaction is a change to green, yellow or red depending on how much glucose is present

What does Biuret test for?

Proteins

What color change do you see if protein is present?

It changes from blue to a purple-lavender to violet.

How did we check for Lipids?

Paper towel test

Translucent (can see through it) when lipids were present.

This is the end.Best of Luck!

CELL Parts and CELL Membrane REVIEW

Name the cell part that corresponds to

the function

Control Center (Brain of the Cell)

The Nucleus

Makes Ribosomes and is found inside the

Nucleus

The Nucleolus

Where proteins are made?

On the Ribosomes

Packages, stores, and distributes proteins; pancake-shaped layers

Golgi Apparatus

Thick fluid inside cells

CYTOPLASM

Hair-like extensions that help cells sense their surroundings

Cilia

Has a double membrane called the “nuclear

envelope”

The Nucleus

Folded membrane that transports proteins throughout the cell

The Endoplasmic Reticulum

Contains chlorophyll, found only in plant

cells

Chloroplast

The “powerhouse” of the cell, site where

ATP is made

Mitochondria

Boundary of the cell, found in both plant and animal

cells

The cell membrane

Digests (breaks down) wastes and old cell parts, kills bacteria and viruses

Lysosome

Tail-like extension that helps move some cells

through watery environments

Flagella

Stores water, wastes, and nutrients for plants

Central Vacuole

Rigid outside boundary for plant cells

Cell Wall

Now let’s examine the Membrane!

What does selective permeability mean?

Selective= choosy, picky, doesn’t let just anything in.

Permeable= allow substances to enter and exit.

Selective permeability= the ability of the membrane to let some things in and keep others out.

The membrane is made of these!

Phospholipid Molecules

They have the following parts:

Phosphate and Glycerol Head (polar)

Fatty Acid Tails (nonpolar)

Why is the membrane so fluid?

Fatty acid tails are unsaturated (kinked) so they don’t compress

Cholesterol is embedded (stuck in) between the tails

What other components make the membrane a

mozaic?

transport proteins

What are three examples of transport proteins?

1. gated proteins

2. channel proteins

3. receptor proteins

Why are transport proteins needed?

They allow substances that are too…

Big, charged or polar to cross the membrane.

What substances can or cannot pass easily across

the membrane?CAN CANNOT

Polarity

Nonpolar PolarSize

Small Large Charge

Uncharged Charged

What is a concentration

gradient?Different concentrations of molecules between two areas.

If there is no difference, there is no gradient—

You have equilibrium!

When is there equilibrium?

When there is an equal concentration of molecules on both sides of a membrane or throughout the space.

Why is it called “Dynamic” Equilibrium?

The molecules are always moving (dynamic), but the concentration stays equal.

Movement of molecules from high concentration to low

concentration

Diffusion

Diffusion of Water Molecules

Osmosis

Two types of Transport:

Active Transport

Passive Transport

Name kinds of Passive Transport-Remember-- no

additional energy requiredDiffusion

Osmosis

Facilitated Diffusion=movement down a gradient for substances that cannot easily cross the membrane– they

need to be helped or assisted by a …….

Transport protein

Name two kinds of Active Transport– these require

energy inputEndocytosis– Endo= IN

Exocytosis- Exo = Exit

Solutions:

Hypertonic

Hypotonic

Isotonic

Which has more dissolved solutes?

Hyper

Which has more H2O?

Hypo

Water always moves from ……

Hypo to Hyper

Hypotonic solutions-- (mo H2O)

To Hypertonic solutions-- more solutes, but less H2O

Plant cells need water to maintain upright structure.

What is this pressure called?

Turgor Pressure

When a plant loses turgor pressure, it loses water from osmosis. That’s called……

Plasmolysis

Thank you and Good-Luck!

Cell Cycle REVIEWaka.. The story of the life of a cell.

What phase does a cell spend most of its time in?

Interphase– subphase=G1

What happens in G1?

The cell is metabolically active=

Performing the chemical reactions needed for the cell to do all the jobs in needs to do

In G1, What is DNA called and what does it look like?Chromatin

A thin, tangled mass (good for directing protein making to catalyze chemical rxns).

What is the G1 checkpoint checking for:

Is the cell healthy enough and large enough to divide?

What happens in S phase?

Synthesis of, Replication of, Duplication of:

DNA

Need two copies of the DNA if the cell is going to divide and make two identical cells from the original

What happens in G2?The DNA coils and condenses.

Each strand joins to its duplicate at the centromere- now called duplicated chromosome made of two sister chromatids.

Centriole is duplicated, too

What does the G2 checkpoint check for?

It checks the DNA to make sure it was copied accurately. If not, repairs can be made or cell can die.

Now for Mitosis!What will divide in Mitosis?

The Nucleus!

How many subphases are there in Mitosis?

4= PMAT

Prophase, Metaphase, Anaphase, Telophase

Describe Prophase.

Nuclear membrane dissolves

Centrioles move to opposite poles

Spindle fibers attach to chromosomes

What happens in Metaphase?

Spindles move the duplicated chromosomes to the equator (midline)

They line up head to toe in a row

AnaphaseDuplicated chromosomes are pulled apart

They are now unduplicated

They move to opposite sides (poles)

Telophase- the last phase of Mitosis

Two nuclei form

The membranes around them form

Spindles break down

Cytokinesis

The cytoplasm is divided and the two separate cells form. They are identical.

In plant cells, a cell plate forms (see above)

In animal cells, the cytoplasm pinches or furrows in (see right).

Identify the following: chromosomes, chromatids,

centromere, centriole, spindle

What does the DNA instruct the cell to make?

Protein

Specifically, enzymes that:

Catayze reactions including the process of cell division

Types of DNA (genes) that start or stop cell

division:Proto-onco genes= accelerator- they tell the cell to go ahead and divide (reproduce)

Tumor suppressor genes= brakes that stop the process of cell division

What is contact inhibition?

Under normal DNA instructions, contact inhibition stops a cell from dividing when it is touching other cells.

But sometimes, things go terribly wrong!

Mutations- What are they?

Changes in DNA caused by:

Mutagens- factors in the environment-

chemicals (tobacco, drugs, cleaning products, pesticides),

energy (radiation, x-rays)

Random mistakes in DNA copied or inherited

These can cause cancer, AKA

Uncontrolled cell growth= the cells divide because there are failures in tumor suppressor and proto-onco genes

The cell is in contact with other cells, but proto-onco genes are turned on and the suppressor genes are turned off.

How is cancer treated?1. Surgery– remove the tumor or group of cells that is dividing rapidly

2. radiation- using concentrated radiation to kill cancer cells

3. chemotherapy- chemicals (powerful drugs) that kill cancer cells

The EndGood luck!

PhotosynthesisIs defined as…

A process by which light energy is converted into chemical energy

Where does this take place?

In the chloroplasts of plant cells

The Basics: Reactants and

Products

The main source of energy for all life is….

The SUN

Photosynthesis is the process of converting sunlight into ATP then into organic molecules that store energy.

ATPHow is ATP like money?

It is: Energy currency -- the only form of energy living things can use (spend).

How does ATP release energy?

By breaking the bond between the 2nd and 3rd phosphate and becoming ADP.

Autotrophs are…

Plants or other organisms that make their own energy from the sun or inorganic compounds (they are producers)

Heterotrophs are consumers that…

Get energy from food by eating plants and animals that eat plants

Where are the stroma and thylakoid space relative to the thylakoid

membrane?

The chloroplast contains thylakoids in a fluid-filled space called the stroma.

The thylakoid space is inside the thylakoid and the membrane surrounds it.

Where is chlorophyll located?

On the thylakoid membrane

What is chlorophyll?

A pigment that absorbs and reflects light

What frequencies of light are absorbed and reflected by

chlorophyll?

Red and blue are absorbed

Green is reflected

What happens to chlorophyll when it absorbs light energy?

It loses excited electrons to the electron transport chain.

How are these electrons replaced?

Photolysis= light splitting water with an enzyme.

What are the three products of photolysis?

1 Oxygen to the atmosphere

2 H+ ions inside the thylakoid membrane

3 Electrons to chlorophyll to replace those lost to the ETC

Describe the ETC:electron transport

chain.

A series of protein molecules embedded on the membrane where each one has a higher attraction for electrons than the previous one.

What happens as the energy is released in each redox reaction?This energy is used to actively transport H+ ions into the thylakoid space against the gradient.

This builds up a higher concentration of H+ in the thylakoid space.

Are H+ freely permeable to the thylakoid membrane? (can they cross easily?)

No-- they are charged!

How do H+ ions diffuse out of the thylakoid space into the stroma?

Through a transport protein called…

ATP Synthetase

Is the flow of H+ ions through ATP Synthase “energy requiring” or

“energy releasing”?

Energy releasing

This energy is used to form ATP

Is the formation of ATP energy requiring or energy releasing?

Energy requiring

Energy is needed to create the bond between the 2nd and 3rd phosphate making ATP from ADP + P

What serves as the final electron acceptor at the end of the electron

transport chain?

NADP+

What happens to create NADPH?

NADP+ combines with the final e- and H+ from the stroma to make NADPH.

NADPH is used in the next phase.

What three things are needed for the light reactions? What three things are produced

in the light reactions?

Needed--Light, water, chlorophyll

Produced--oxygen (to atmosphere), ATP, and NADPH (to dark reactions)

The dark reactions, AKA -- the light independent reactions, are also

known as…

The Calvin Cycle

What is carbon fixation and where does the carbon come from?

CO2 from the air is added to a 5 Carbon sugar = this is “carbon fixation”

Glucose is produced

What is NADPH used for?

It carries electrons and H+ ions to the Calvin Cycle.

These are used to build glucose molecules.

What enzyme is key to this process?

Rubisco

Explain the results of the Photosynthesis LabWhat light treatments had the highest and the lowest rate of reaction?

What role did DPIP (blue stuff) play in the photosynthesis reaction?

Now that you know all about photosynthesis..Don’t forget to hug a tree!

Without photosynthesis, we would not have air to breath or food to eat.

THE END ?

Define Cellular Respiration.

The process in which biomolecules, like sugar, are converted into an energy form that living things can use (ATP).

How many types of Cellular Respiration are

there?

Two Types: Aerobic or Anaerobic

Distinguish between these.

With or without oxygen

How much ATP does each yield?

Aerobic yields 36 or 38 ATP

Anaerobic yields only 2, but gives NAD back to glycolysis to keep the process going.

What do cells do with the energy they get from

food?Store it as ATP or

Release as heat

Chemical EquationsPhotosynthesis: light energy converted to chemical energy

CO2 + H2O + light O2 + glucose

Cellular Respiration: biomolecules converted to ATP

O2 + glucose CO2 + H2O + ATP

Where is the energy stored in biomolecules like sugars, carbs,

lipids, etc.?

In the bonds between the atoms

Where in the bonds is energy stored in ATP?

In the bond between the second and third phosphate

How do living things access and convert the energy stored in

biomolecules?

Break existing bonds and form new ones

What is the name for the series of reactions that converts the stored

energy in biomolecules into molecules of ATP?

Cellular Respiration

What is the first stage of cellular respiration called?

Glycolysis

Where does this step occur?

In the Cytoplasm

Is this aerobic or anaerobic?

Anaerobic

What are the products of this step?

ATP, NADH, and 2 3-C Pyruvate molecules

What is the net production of ATP in this step?

2 ATP’s

If oxygen is available where do the pyruvates

go?

To the Mitochondria

What type of Cellular Respiration is this?

Aerobic

What happens in the Prep Step?

The pyruvates are transported into the mitochondria.

They lose a carbon (CO2 given off)

2 carbon acetates are formed—they use NAD and Co enzyme A to become…

acetyl Co A

Diagram and describe the events of the prep step (pyruvate conversion)

2 3-C pyruvate molecules are converted to…

2 2-C acetate molecules with the production of…

2 molecules of NADH and 2 molecules of CO2

Diagram the events of the Kreb’s Cycle indicating the number of NADH, FADH2, ATP,

and CO2 molecules produced

The Krebs Cycle produces electron carriers a CO2 is released leaving…

6 NADH, 2 FADH2, 2 ATP, 4 CO2

What is the significance of the 6 CO2 molecules produced in the Prep Step and

Kreb’s Cycle?

The four carbons in the four CO2 molecules plus the two carbons in the two CO2 molecules from the prep step are evidence that the initial six carbon sugar molecule is completely broken down

Describe what the electron transport chain is and where it is located in the

mitochondria.

The ETC is a series of protein molecules embedded on the inner membrane of the mitochondria that each have a higher attraction for electrons than the previous one.

What is the source of electrons to the electron transport chain?

The co-enzymes NADH and FADH2

Every time an electron is accepted and released by a protein in the electron transport chain –

a redox reaction releases a small amount of energy used to do what?

Actively transport a H+ ion from the matrix into the outer compartment

What happens when a molecule is reduced?

It accepts electrons.

What happens when a molecule is oxidized?

It loses electrons.

What is this reaction called?

A Redox Reaction.

Mnemonic Strategy

LEO the lion says GER

Lose Electrons=Oxidize

Gain Electrons=Reduce

Where do H+ ions become highly concentrated?

In the Outer compartment

Are these ions freely permeable to the membrane?

No, so…how can they diffuse through the membrane into the inner compartment?

Through ATP Synthetase transport proteins.

Is the diffusion of H+ ions energy releasing or energy requiring?

Releasing

Is the formation of ATP from ADP energy releasing or energy requiring?

Requiring

Link these two statements in explaining the formation of ATP.

The energy released in the diffusion of H+ is required to form ATP.

How many ATP molecules can be created from the electrons delivered by NADH?

3/NADH

How many ATP molecules can be created from the electrons delivered by FADH2?

2/FADH2

What serves as the final electron acceptor in aerobic

respiration?

Oxygen

What happens to pyruvates if oxygen is not available?

Pyruvates stay in the cytoplasm and participate in Lactic Acid Fermentation pathways.

Diagram the lactic acid anaerobic respiration pathway that occurs in animals

2 3-C Pyruvates-->2 3-C Lactic Acid

2 NAD+ molecules are produced in this step

What products from lactic acid fermentation are re-cycled in

the respiration pathways?NAD+ to re-start glycolysis

How many ATP molecules per glucose are formed in lactic

acid fermentation?2 ATP’s/glucose

Why do you “feel the burn” when you are

exercising strenuously?

Lactic acid fermentationThere is a build up of lactic acid in the muscles due to anaerobic lactic acid fermentation.

Give two reasons why muscles can’t contract well when fatigued during strenuous

exercise.

1. Only get 2 ATP per glucose due to anaerobic respiration.

2. Lactic acid molecules build up in muscles and interfere with muscle contractions.

Why is it valuable that animals can respire

anaerobically?It allows animals to exert energy at a high intensity for a short period of time– times of stress for fighting or fleeing.

If we were not able to do anaerobic respiration, we would pass out when we had a decrease of oxygen

What kind of fermentation do yeasts and bacteria

undergo?Alcoholic fermentation

Diagram the ethyl alcohol anaerobic respiration pathway

2 3-C Pyruvates-->2 2-C Ethyl Alcohol + 2 CO2

2 NAD+ molecules are produced in this step

Compare: Photosynthesis and Cellular Respiration

Location: Where does each take place?

Photosynthesis happens on the chloroplast.

Aerobic Cellular respiration happens in the the mitochondria.

Both build up a concentration of hydrogen to power the transformation of ADP into ATP.

Compare -- Photosynthesis vs. Cellular respiration

Source of electrons:

Photosynthesis gets electrons from—breakdown of water molecules (photolysis).

Cellular respiration gets electrons from—breakdown of biomolecules in the Kreb’s cycle source of FADH2 and NADH.

Final electron acceptors=

NADP+ in photosynthesis

Oxygen in aerobic respiration.

CyclesPhotosynthesis has Calvin cycle….

adds carbon to make sugar.

Cellular Respiration has the….

Krebs cycle– breaks down biomolecules creates source of electrons and ATP for larger production of ATP

Compare--- Organisms that do photosynthesis and cellular

respiration.

Photosynthesis happens …only in plants.

Cellular respiration in both plants and animals.

ReviewCellular respiration –Three basic stages:

Glycolysis, Krebs Cycle, ETC.

Glycolysis yields 2 ATP

Aerobic respiration (Krebs and ETC) yields:

36 or 38 ATP

If no oxygen is available..

Fermentation begins and NAD+ is recycled back into..

Glycolysis which continues until…

Oxygen is available.

ReviewTwo kinds of fermentation:

Alcoholic and Lactic Acid

Alcoholic fermentation is done by:

Yeast, bacteria, fungus and creates foods like

Beer, wine, cheese, bread

Lactic acid fermentation happens in

animals and some bacteria. It causes..

Sore muscles after anaerobic exercise.

The EndGood Luck!