Key Idea #14 Cells in all multicellular organisms are specialized to

take in nutrients, which they use to provide energy for the work that cells do and to make the materials that cells or organisms need.

http://library.thinkquest.org/C004535/media/cell_membrane.gif

Chemical Compounds in Cells

Nutrients taken in by the cell provide materials to build cell organelles build specialized molecules used by the

organisms, including: – carbohydrates– lipids (fats)– proteins– nucleic acids: DNA and RNA

In plants, water and carbon dioxide are taken in by the plant and used to produce carbohydrates, proteins and fats (lipids).

Carbohydrates are energy-rich compounds

made of the elements carbon, hydrogen, and oxygen.

are an important part of cell membranes and cell walls.

include sugars found in fruits and some vegetables.

include starches found in potatoes, corn, rice, and wheat bread which your body breaks down into glucose (a sugar).

Proteins are large organic molecules

made of carbon, hydrogen, oxygen, nitrogen and sulfur.

are found in foods such as meats, eggs, fish, nuts and beans.

form parts of cell membranes. make up many of the

organelles found in cells. are used by cells in your body

to build body parts such as hair and nails.

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publications.nigms.nih.gov

Fats (Lipids) are energy-rich compounds

made of carbon, hydrogen, and oxygen.

include fats, oils, and waxes found in seeds.– Peanuts, almonds walnuts

(fat)– Sunflower (fats)– Olive (oil)– avocado (oil)

include cholesterol.– an important part of animal cell

membranes– Meat, cheese, and eggs are all

high in cholesterol.

The jojoba (Simmondsia chinensis), a native shrub of the southwestern United States produces seeds and liquid wax.

The white, solid wax is produced by hydrogenation of the unsaturated liquid wax.

Hydrogenation is the process that involves the addition of hydrogen to the fatty acids under heat and pressure.

FYI

Nucleic Acids are very large organic

molecules made of carbon, oxygen, hydrogen, nitrogen, and phosphorus.

contain the instructions needed to carry out life.– DNA:

• genetic material that contains the information that is passed from parent to offspring

– RNA:• important for protein

production• found in the cytoplasm

and nucleus

Plants are multicellular organisms that produce their own food.

Plants use energy from light to make sugar molecules from the atoms of carbon dioxide and water.

Plants use these sugars along with minerals from the soil to form fats, proteins, and carbohydrates.

Fats, proteins and carbohydrates can be used immediately, incorporated into the cells of a plant as the plant grows, or stored for later use.

Water helps cells keep their

size and shape. is important because

most chemical reactions in cells require water.

botany.thismia.com

Cell Membrane acts as a gatekeeper is selectively permeable and controls what

substances can enter or leave the cell is permeable to oxygen, water, and carbon dioxide

– (they can pass through it)

is not permeable to some large molecules and salts– (they can’t pass through it)

Substances that can move into and out of a cell use one of three methods: diffusion osmosis active transport

Diffusion – Molecules in Motion Diffusion is the main

method by which small molecules move from an area of higher concentration to an area of lower concentration.

http://www.mrphome.net/physics/diffusion/index.html

Diffusion occurs when molecules bump

into each other and eventually spread out evenly throughout an area.

Diffusion and Osmosis

Osmosis is the diffusion of only

water molecules through a selectively permeable membrane.

is important to cells because they can’t function properly without adequate water.

http://www.biologycorner.com/resources/osmosis.gif

Note: Only water molecules pass through the cell membrane during osmosis.

Active transport uses the cell’s energy (ATP) to help nutrients enter the cell that can’t pass through the cell membrane by diffusion.

Active Transport

Active transport examples: Engulfing

Transport proteins in the cell membrane pick up molecules outside the cell and carry them inside.

http://www.nicksnowden.net/images/Membranes_and_Transport/endocytosis.gif ; phschool.com.jpg