Proteins• Proteins are

made of Amino Acid chains• Amino acids

are linked in a sequence

Ribosomes• Proteins are

bonded together at the ribosomes • # 2 on

diagram

Ribosomes

Sequence determines shape• Order of amino

acid chain determines a proteins shape• Shape

determines its function

Examples of Proteins • Receptor

molecules• Nerve chemicals• Hormones• Enzymes

Proteins have shapes

Receptor Molecules• Located on

surface of membrane to receive signals from nerve chemicals or hormones

1 2 3

Receptor molecules• Located on

the surface of cells• on the cell

membrane

3-D view of receptor molecules

•What kind of molecules are receptors?• Proteins

Cellular Communication•Receptor

molecules are used so cells can interact

Receptor molecules are Proteins

• They have a specific shape• Signals they

receive must have a shape that can fit into them

Receptor Signal

Primary Agents to Communicate

•Hormones•Chemicals

produced by nerve cells

Receptor molecule

Receptor and Hormone• Another

pictorial example of a receptor molecule and a hormone

Hormones• Signals released by

glands so cell can communicate with

• Hormone has to fit on receptor molecule of the target cell

Amino acid molecules are bonded together in a specific sequence on cell structures known as 1.ribosomes2.vacuoles3.mitochondria4.centromeres

The shape of a protein is most directly determined by the1.amount of energy available for synthesis of the protein2.kind and sequence of amino acids in the protein3.type and number of DNA molecules in a cell4.mistakes made when the DNA is copied

A characteristic shared by all enzymes, hormones, and antibodies is that their function is determined by the

1.shape of their molecules 2.DNA they contain 3.inorganic molecules they contain 4.organelles present in their structure

Nerve cells are essential to an animal because they directly provide1.communication between cells2.transport of nutrients to various organs3.regulation of reproductive rates within other cells4.an exchange of gases within the body

Which substances are found on cell surfaces and respond to nerve and hormone signals?1.starches and simple sugars 2.subunits of DNA 3.vitamins and minerals 4.receptor molecules

Letter B indicates a1.ribosomes2.receptor molecules3.tissues4.inorganic substances

Base your answer on the diagram and on your knowledge of biology. Which statement best describes the diagram?1.Nerve cell X is releasing receptor molecules.2.Nerve cell Y is signaling nerve cell X.3.Nerve cell X is attaching to nerve cell Y.4.Nerve cell Y contains receptor molecules for substance A

Cellular communication is illustrated in the diagram below. Information can be sent from1.cell A to cell B because cell B is able to recognize signal 12.cell A to cell B because cell A is able to recognize signal 23.cell B to cell A because cell A is able to recognize signal 14.cell B to cell A because cell B is able to recognize signal 2

Cellular communication is illustrated in the diagram below.

Information can be sent from1.cell A to cell B because cell B is able to recognize signal 12.cell A to cell B because cell A is able to recognize signal 23.cell B to cell A because cell A is able to recognize signal 14.cell B to cell A because cell B is able to recognize signal 2