Are we really what we eat?What is what we eat?

Organic molecules

Where does what we eat come from?

Photosynthesis

What happens to what we eat?Enzymes

Cell transportCellular Respiration

Carbon cycle

How are our bodies specialized to use what we eat?

Cell organellesCell Specialization Gene Regulation

How can a meal become a growing strand of hair?

Mitosis Protein synthesis

Why can we eat the same things, but grow different looking hair?

MeiosisMolecular heredity

Patterns of inheritance

Why do some people have no hair?• Causes of disease

Driving Questions for Photosynthesis

and Cellular Respiration

• Nutrients consist of various chemical substances that make up our diet. We require a certain amount of nutrients to carry out essential life processes which require ENERGY!!!!

• Which of the 4 organic molecules provide us with energy? How?

1. Proteins

2. Carbohydrates

3. Lipids

4. Nucleic Acids

What is what we eat?

Energy• Is the capacity to do work which

comes from the breaking of bonds and rearranging them to form new, and sometimes very different, products during a chemical reaction

• Matter is formed by energy

Watch:http://www.youtube.com/watch?v=-a-kLYerQl8

Through 5:52

- Exothermic

- Endothermic

What is what we eat?

Exothermic• Combustion is an example of an exothermic

process. It is an exothermic chemical reaction (give out heat to the surroundings). E.g., Burning of coal

• The common observation in these reactions is that oxygen combines with carbon to release heat. These chemicals like coal or butane are known as fuels. Most of the fuels contain carbon and release carbon dioxide on combustion. The cleanest fuel is hydrogen because the product is water which is non polluting.

Energy

Endothermic

• Photosynthesis is an example of an endothermic chemical reaction. In this process, plants use the energy from the sun to convert carbon dioxide and water into glucose and oxygen. This reaction requires 15MJ of energy (sunlight) for every kilogram of glucose that is produced

Energy

Matter• Determined by the vibrations of

atoms (solids have a much higher vibration, or frequency, than gases)

Energy

Proteins• Composed of Carbon (C), Hydrogen (H),

Oxygen (O) and Nitrogen (N)

• Enzymatic proteins catalyze chemical reactions by providing the activation energy

• Proteins from plant sources only have some of the amino acids we need (this is why vegetarians must use supplements)

What is what we eat?

• Proteins from animal sources have all of the essential amino acids we need

Carbohydrates• Major source of energy for the body

• Composed mostly of Carbon (C), Hydrogen (H) and (O)

• When these elements bond they provide energy for the body in the form of kilocalories (kcal)

What is what we eat?

The body breaks down carbohydrates into its monomers called…..?

Glucose!!!!

Lipids• Composed of Carbon (C),

Hydrogen (H) and Oxygen (O)– There are fewer O than in

Carbohydrates

• There are two types:1. Saturated

• Mostly from animals, solid at room temperature

• Saturated fatty acids can cause an increase in cholesterol leading to the clogging of arteries and heart disease

2. Unsaturated • Mostly from plants, liquid

at room temperature• Unsaturated fatty acids

help to regulate blood pressure and help to repair cell parts

What is what we eat?

Nucleic Acids• Do not provide us with energy

• Deoxyribonucleic Acids (DNA) are where the instructions for cellular activities come from

• Ribonucleic Acids (RNA) are involved in the production of proteins– We know some proteins are

enzymatic and help to catalyze reactions by lowering activation energy

What is what we eat?

Where does what we eat come from?

Photosynthesis

Overview

Step 1

Step 2

Step 3

Photosynthesis

• Photosynthetic autotrophs use sunlight energy to power chemical reactions which convert CO2 and water into food for themselves like carbohydrates such as cellulose (helps the plant stand up tall), starch, and oxygen which is released into the atmosphere

CO2 + Water Sugar + Oxygen

Light

http://www.youtube.com/watch?v=R_17euLU_EM&feature=related

Insert youtube link to photosynthesis rap video

http://www.pbs.org/wgbh/nova/methuselah/photosynthesis.html

Useful Links:

Where does what we eat come from?

1. CO2 + Water make Glucose

• CO2 and water undergo a chemical reaction and glucose is produced

Photosynthesis

2. Two things can happen to glucose…

1. It can be burned through cellular respiration to make energy for the plant

2. It can be strung together to make carbohydrates like starch and cellulose which help the plant to stand up tall

Photosynthesis

3. Special molecules and structures

• Special molecules called chlorophyll, a green pigment located within specialized structures called chloroplasts which provide a place for photosynthesis to occur

Photosynthesis

What happens to what we eat?

1. Catalytic proteins called enzymes provide the activation energy required to jump start cellular respiration which converts substrates into products

2. Homeostasis is maintained by either the release or uptake of glucose

3. Cellular respiration is the chemical reaction that converts glucose into CO2 and water

4. Finally, energy flows and nutrients cycle!

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Enzyme involvement in cellular respiration

What happens to what we eat?

• Special enzymes speed up the reaction where sugar (solid) substrate bonds are broken and rearranged to form the products H2O and CO2 (gases)

Homeostasis• The blood glucose level is the amount of glucose in

the blood. Glucose is a sugar that comes from the foods we eat, and it's also formed and stored inside the body. It's the main source of energy for the cells of our body, and it's carried to each cell through the bloodstream. Blood glucose levels are regulated by the pancreas and the liver to maintain the delicate balance in the body.

What happens to what we eat?

Click the yellow Click the yellow circles for more circles for more informationinformation

How our bodies use glucose

Hyperglycemic• High blood sugar levels

happen when the body either can't make insulin (Type 1 Diabetes) or can't respond to insulin properly (Type 2 Diabetes). The body needs insulin so glucose in the blood can enter the cells of the body where it can be used for energy. In people who have developed diabetes, glucose builds up in the blood, resulting in hyperglycemia.

• Having too much sugar in the blood for long periods of time can cause serious health problems if it's not treated. Hyperglycemia can cause damage to the vessels that supply blood to vital organs, which can increase the risk of heart disease and stroke, kidney disease, vision problems, and nerve problems in people with diabetes.

Homeostasis

Hypoglycemic

• Hypoglycemia, also called low blood sugar, occurs when blood glucose drops below normal levels. When blood glucose begins to fall, glucagon—another hormone made by the pancreas—signals the liver to break down glycogen and release glucose into the bloodstream. Blood glucose will then rise toward a normal level. In some people with diabetes, this glucagon response to hypoglycemia is impaired.

Homeostasis

Cellular Respiration

– Aerobic Respiration– Anaerobic Respiration

What happens to what we eat?

Useful Links:

http://www.youtube.com/watch?v=3z6dq-T68zs

Aerobic Respiration

• The breakdown of sugars in the presence of oxygen to produce ATP energy, CO2 and Water

Cellular Respiration

Anaerobic Respiration

• Two Types:– Alcoholic Fermentation– Lactic Acid Fermentation

• The breakdown of sugars in absence of oxygen, or “without air”, to produce ATP energy

Cellular Respiration

Alcoholic Fermentation

• After sugar and starch have metabolized, pyruvic acid (coenzyme) is the end product which then teams up with NADH and undergoes a chemical reaction which yields the products alcohol, CO2 and NAD+

– Yeast, beer, wine and root beer When yeast run out of oxygen, they begin to ferment which releases alcohol and CO2. The CO2 causes air spaces which make the dough rise and the alcohol is burned off during baking.

Anaerobic Respiration

Lactic Acid Fermentation

• In many cells pyruvic acid accumulates as a result of the breakdown of sugars (glycolysis), through a chemical reaction the reactants can be converted into lactic acid and NAD+ which is used to power more glycolysis

• This process can happen in our muscles if our cells aren’t getting enough oxygen during exercise

Anaerobic Respiration

Photosynthesis vs. Cellular Respiration

Mitochondria

Chloroplast

Energy flows and nutrients cycle

• Energy flows from the sun to the autotrophs which do photosynthesis. Consumers like humans use the starch/sugars from plants we eat and the oxygen they provide us to breathe to produce ATP energy, CO2 and H2O

What happens to what we eat?

- Energy

- Nutrients

Energy

• Energy gets used up during chemical reactions, 1% of the suns energy gets passed on to the producers and only 10% is passed on to the higher trophic levels thereafter

En

erg

y F

low

s

Energy flows and Nutrients cycle

Nutrients• Nutrients flow throughout a system

– Example: CO2 is sequestered by plants from the atmosphere, the plants use the CO2 to make glucose and O2. Plants use the glucose to get energy and to make cellulose/starch to stand up tall. Humans breathe oxygen and use it for the process of cellular respiration which produces CO2 that returns to the atmosphere and water. Additionally, when decomposers break down dead organic matter, they release CO2 into the air and some is stored in fossil fuels.

Energy flows and Nutrients cycle

How are our bodies specialized to use what we

eat?

• All living things are made up of cells. Our bodies are made up of a certain kind of cells and the bacteria that makes us sick are another type of cells.

• There are two types of cells:1. Eukaryotes

2. Prokaryotes

Which types of cells are we made up of and which type are bacteria?

Levels of organization in living things

Not Living

Click for Example

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Levels of Organization

Nucleus (Boss)

Nucleus- contains nearly all the cell's DNA and with it the coded instructions for making proteins and other important molecules

Endoplasmic Reticulum (ER)- internal membrane system in cells in which lipid components of the cell membrane are assembled and some proteins are modified

Golgi Apparatus- stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

Vesicle- used to transport raw material into the cell to be broken down into smaller usable parts

Organelles (Little Organs)

AND MANY MORE

(Chapter 7-2 in Textbook)!!!!

Which organelles do you think would be the most

common in muscle cells?

This “power house” converts the chemical energy stored in food into compounds that are more convenient for the cell to use Levels of Organization

CellCells are the basic units of structure of all living things. Most living things are composed of two cell types, either plant or animal cells. Cells can be highly specialized.

1. Animal Cell

2. Plant Cell

Levels of Organization

Related Links:

http://www.cellsalive.com/cells/cell_model.htm

:http://www.youtube.com/watch?v=uyM-0UxdzKU&feature=related

http://www.youtube.com/watch?v=WdEP6GsQ9L4&feature=related

En Espanol:

http://www.youtube.com/watch?v=6fbwQGioDuI&feature=related

Cell boundaries

Cell Limitations

Cell Specialization

• Cells develop in different ways to be able to perform different tasks.

Cell

Animal Cells• Animal cells are typical of the eukaryotic cell,

enclosed by a plasma membrane and containing a membrane-bound nucleus and organelles. Unlike the eukaryotic cells of plants and fungi, animal cells do not have a cell wall. This feature was lost in the distant past by the single-celled organisms that gave rise to the kingdom Animalia.

Cell

Eukaryotes

Related Links:

http://micro.magnet.fsu.edu/cells/animalcell.html

Plant Cells• Plants are unique among the eukaryotes,

organisms whose cells have membrane-enclosed nuclei and organelles, because they can manufacture their own food. Chlorophyll, which gives plants their green color, enables them to use sunlight to convert water and carbon dioxide into sugars and carbohydrates, chemicals the cell uses for fuel. They also have a cell wall.

Cell

Eukaryotes

Related Links:

http://micro.magnet.fsu.edu/cells/plantcell.html

Cell boundaries• All cells are bordered by a thin,

flexible barrier, selectively permeable barrier called the plasma membrane (PM) that has two functions:

1. Regulates what enters and leaves the cell2. Provides protection and support for the ce

ll• Some cells also have “walls”

Cell

Cell Limitations

Cell

• Recall:– A solution is a mixture of 2 or more

substances– The liquid doing the dissolving is the

solvent (usually water)– The solid being dissolved is the

solute– The concentration is the mass of

solute in a given solution (mass/volume)

Cell Limitations (cont.)

• Cells are limited in their size because of 3 things:– 1. Diffusion

– Osmosis– Facilitated Diffusion

– 2. DNA– 3. Food Requirements

Diffusion• Does not require use of cell’s energy (passive transport)

• Particles move constantly in a solution, colliding with each other. As a result they tend to spread out to areas where they are less concentrated (have more “elbow room”)

• Equilibrium is reached when the concentration of solute is the same on both sides of the membrane

Cell Limitations (cont.)

Osmosis• Does not require cell’s energy (passive

transport)• Water can move freely through the

selectively permeable plasma membrane.

– Isotonic-concentration the same on both sides

– Hypertonic-solution with greater concentration of solutes

– Hypotonic-solution with the lesser concentration of solutes

High Concentration Low Concentration

Cell Limitations (cont.)

Video Link: http://www.pearsonsuccessnet.com/snpapp/iText/products/0-13-181118-5/bm/vaosmosi.html

Osmosis and Cells• Osmosis plays an important role in maintaining

homeostasis through the intake and loss of water. Osmosis exerts osmotic pressure on the hypertonic side causing a cell surrounded by fresh water to be flooded. The cell will burst (lysis) if it gains too much volume.

• Blood cells in animals are isotonic and have roughly the same amount of dissolved materials as inside the cell

• Plant cells have cell walls that prevent the cell from swelling and bursting when in contact with water

Cell Limitations (cont.)

Jump In: OsmosisWhat kind of membrane is this?

Which direction will the water flow?

Which cell is in an isotonic, a hypertonic and

a hypotonic solution?1.

2.

3.

Cell Limitations (cont.)

Facilitated Diffusion • Does not require cell’s energy (passive

transport)

• The cell’s plasma membrane has protein channels that help larger solute molecules who wouldn’t normally be allowed in, pass through more easily.

Oxygen diffusion through the blood for transport to mitochondria for cellular respiration

Cell Limitations (cont.)

Video Link: http://www.pearsonsuccessnet.com/snpapp/iText/products/0-13-181118-5/bm/vapassi.html

- Red blood cells have a protein channel that facilitates the diffusion of glucose in and out

Active Transport

• Cell’s sometimes need to move materials against a concentration gradient (low to high)

• This process requires

much of the cell’s daily energy

• Generally carried out at PM by protein “pumps” or by processes called endocytosis and exocytosis

Video Links: Active Transport http://www.pearsonsuccessnet.com/snpapp/iText/products/0-13-181118-5/bm/vaactive.htmlEndocytosis and Exocytosishttp://www.pearsonsuccessnet.com/snpapp/iText/products/0-13-181118-5/bm/vaendocy.htmlCell Limitations (cont.)

Endocytosis and Exocytosis

Endocytosis1. “Cell eating”

– The PM engulfs food particles and package them in a food vacuole called a vesicle.

2. “Cell drinking”– Tiny pockets form along PM and fill with

water. They pinch off inside the cell

Exocytosis1. The membrane of a contractile

vacuole carrying waste or cellular material fuses with the PM and forces its contents outside the cell

Cell Limitations (cont.)

Jump In:

Which molecule(s) do you think will diffuse across the Plasma Membrane most quickly? Why? What

kind(s) of transport will be used?

Which molecules do you think will diffuse across the Plasma Membrane least quickly? Why? What kind(s) of transport will

be used?

What is the relationship between molecule size and the rate of diffusion?

The smaller the molecule, the The smaller the molecule, the faster it will diffuse and most faster it will diffuse and most

likely passive transport is likely passive transport is used.used.

Plasma Membrane: Entry and Exit

• The membrane is a double-layered sheet called a lipid bilayer with embedded proteins and carbohydrates. The proteins act as channels or pumps to move raw materials in through the membrane and cell products outward. The membrane’s carbohydrates are important in cell-cell identification.

Cell Boundaries

Plasma Membrane: Protection and Support

• The lipid bilayer aides in protecting the cell from its surroundings and provides support for the cell’s contents.

The “Bouncer” of the cell

Cell Boundaries

Cell Wall

• Plants, algae, fungi and many prokaryotes have a “wall” outside their plasma membrane. The cell wall provides additional protection and support for the cell. The wall is made of carbohydrate and protein fibers like cellulose. Cellulose is the principle component of wood and paper!

Which of the four organic compounds does a book

belong to?

Carbohydrates!!!

Carbohydrates!!!

Cell Boundaries

Plant Cells

Tissue• Group of similar cells that perform a

specific function• Four types

1. Muscle2. Epithelial3. Nervous4. Connective

Levels of Organization

Organ• Some tasks are

too complicated for one type of tissue to handle. This is when several types of tissues work together to perform specialized tasks.

• Each muscle is an individual organ.

Levels of Organization

Organ System

• While organs complete specialized tasks, groupings of organs also work together to perform a specific function. This is called an organ system.

Levels of Organization

Organism

• Multicellular organisms are the sum of all the specialized cells which make the different tissues which are arranged into organs. Organs come together to form an organ system.

• Unicellular organisms are composed of only one cell.

Levels of Organization

Eukaryotes• Eukaryotic cells are more complex and contain

many highly specialized structures called organelles. Eukaryotic cells differ from prokaryotic cells in that they have a nucleus which houses and separates their genetic material from the rest of the cell.

• Animal Cells• Plant Cells

• Like a factory

How are our bodies specialized to use what we eat?

Cells are like factories• Just like a factory needs many

different machines and operators to function, the cell needs different organelles (little organs) to do their job.

Informational Video Link

Eukaryotes

Prokaryotes• Prokaryotic cells are small and

simple. There genetic material is not contained in a nucleus and instead free floats in the cytoplasm.

How are our bodies specialized to use what we eat?

How can a meal become a growing

strand of hair?• TBA

Why can we eat the same things but grow different

looking hair?

• TBA

Why do some people have no hair?

• TBA