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Cells and Tissues
(Part 2)
Coach Vance
Anatomy and Physiology
Cell Physiology
 Membrane Transport – movement of
substances into and out of the cell
 2 Basic Methods of transport
 Passive transport – no energy is required
 Active Transport – requires energy
Solutions
 Solution – a mixture of 2 or more
components
 Solvent – dissolving product
 Solutes – components in smaller quantities
within a solution
Selectively Permeable
 The plasma membrane allows some
material to pass while excluding other
materials.
 This permeability includes movement into
and out of the cell
Passive Transport
Processes
 Diffusion
 Particles tend to distribute themselves evenly in a
solution
 Movement is from high concentration to low
concentration
 Types of diffusion:
 Simple diffusion – unassisted process; solutes are small
enough to pass through pores
 Osmosis – simple diffusion of water
 Facilitated diffusion – requires a protein carrier for transport
 Filtration – water and solutes are forced through the
membrane by fluid
Active Transport
Processes
 Transport substances that are unable to
pass by diffusion due to several reasons:
 They may be too large
 They may not be able to dissolve in the core
of the membrane
 2 common forms of active transport:
 Solute pumping
 Amino acids, some sugars, and ions are
transported by solute pumps by using
protein carriers
 ATP energizes protein carriers
Active Transport
Processes (continued)
 2 common forms of active transport
(continued)
 Bulk transport with the help of ATP
 Exocytosis – moves materials to the outside of
the cell
 Endocytosis – substances are engulfed by being
enclosed in a vesicle
 2 types of Endocytosis:
 Phagocytosis – cell eating
 Pinocytosis – cell drinking
Cell Life Cycle
 Cells have two major periods:
 Interphase – cell growth
 Cell division
 Cell replicates itself
 Function to produce more cells for growth
Events of Cell Division
 Mitosis
 Division of the nucleus
 Result in the formation of 2 daughter nuclei
 Cytokinesis
 Division of the cytoplasm
 Begins when mitosis nears completion
 Results in the formation of 2 new daughter
cells
Stages of Mitosis
 Interphase
 No cell division occurs
 The cell carries out normal growth
 Prophase
 First part of cell division
 Centrioles migrate to the poles
 Metaphase
 Chromosomes are aligned in the center of the cell
Stages of Mitosis
(continued)
 Anaphase
 Daughter chromosomes are pulled toward
the poles
 The cell begins to elongate
 Telophase
 Daughter nuclei begin to form
 A CLEAVAGE FURROW (for cell division)
begins to form
Stages of Mitosis
Prophase
Anaphase
Metaphase
Telophase
DNA Replication
 Genetic material is duplicated and gets
the cell ready for division
 Occurs toward the end of Interphase
 DNA uncoils and each side serves as a
DNA copy
Protein Synthesis
 Gene – DNA segment that carries a
blueprint for building one protein
 Proteins may have many functions:
 Building materials for cells
 Act as enzymes (biological catalysts)
 RNA is essential for protein synthesis
Role of RNA
 Transfer RNA (tRNA) – transfers amino
acids to the ribosome for building the
protein
 Ribosomal RNA (rRNA) – helps form the
ribosomes where proteins are built
 Messenger RNA (mRNA) – carries the
instructions for building a protein from the
nucleus to the ribosome
Transcription and
Translation
 Transcription – transfer of information
from DNA’s base sequence to the
complimentary base sequence of mRNA
 Translation – base sequence of nucleic
acid is translated to an amino acid
sequence
 Amino acids are the building blocks of
proteins
 DNA RNA Protein