chapter 3 cell structure and function what are elements and compounds? how is water important to the...
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Chapter 3 Cell Structure and Function
What are elements and compounds?How is water important to the function of cells?What are the functions of carbohydrates, lipids, proteins, and nucleic acids?
Section 3: Chemical Compounds in Cells
Chapter 3 Cell Structure and Function
Elements and Compounds
Elements = any substance that cannot be broken down into simpler substances
Compounds = the chemical combination of 2 or more elements
Chapter 3 Cell Structure and Function
Elements and CompoundsCarbon dioxide, which is found in gas bubbles, is a chemical compound. So is water.
Chapter 3 Cell Structure and Function
Compounds in Bacteria and Mammals
All cells contain carbohydrates, lipids, proteins, and nucleic acids, as well as water and other inorganic compounds. But do all cells contain the same percentages of these compounds? The graph compares the percentage of some compounds found in a bacterial cell and a cell from a mammal.
Chapter 3 Cell Structure and Function
Compounds in Bacteria and Mammals
Red bars represent percentages of compounds in bacterial cells; blue bars represent percentages of compounds in mammalian cells.
Reading Graphs:
What do the red bars represent? What do the blue bars represent?
Chapter 3 Cell Structure and Function
Compounds in Bacteria and Mammals
About 70%; the percentages are the same.
Interpreting Data:
What percentage of a mammalian cell is made up of water? How does this compare to the percentage of water in a bacterial cell?
Chapter 3 Cell Structure and Function
Compounds in Bacteria and Mammals
Proteins
Interpreting Data:
Which kind of compound–proteins or nucleic acids–makes up the larger percentage of a mammalian cell?
Chapter 3 Cell Structure and Function
Compounds in Bacteria and MammalsDrawing Conclusions:
In general, how do a bacterial cell and mammalian cell compare in their chemical composition?
They are similar, though mammalian cells have a lower percentage of nucleic acids, and bacterial cells have a lower percentage of lipids and fewer proteins.
Chapter 3 Cell Structure and Function
Water
• Most chemical reactions required for life within cells could not take place without water.
–Water dissolves chemicals that cells need
–Plants need water to make sugar
–Water helps cells keep their size and shape
–Water helps insulate cells
Chapter 3 Cell Structure and Function
Organic and Inorganic Compounds
• Organic Compounds
–Contain Carbon, among other elements
–Made by living things
• Inorganic Compounds
–Do not contain Carbon
Chapter 3 Cell Structure and Function
Carbohydrates
• Provide Energy
• Important components of cell parts
• Sugars, Starches, Cellulose, etc.
Chapter 3 Cell Structure and Function
Lipids
• Highly concentrated energy source
• Store energy
• Make up cell membranes
• Fats, Oils and Waxes
Chapter 3 Cell Structure and Function
Proteins
• Make up many structures and organelles
• Made of chains of Amino Acids
• Make up Enzymes
–Perform important functions in the chemical reactions that must take place in cells
Chapter 3 Cell Structure and Function
Links on Proteins
Click the SciLinks button for links on proteins.
Chapter 3 Cell Structure and Function
Nucleic Acids
• Contain the instructions that cells need to carry out all of the functions of life
• DNA and RNA