Copyright (c) by W. H. Freeman and Company
Chapter 1
The Dynamic Cell
Copyright (c) by W. H. Freeman and Company
1.1 Molecular evolution
Evolution is an historical process that dictates the form and structure of life
Evolution ultimately depends on alterations in the structure and organization of genes and gene products
Fundamental aspects of cellular life are shared by different organisms and dependent on related genes
Small changes in certain genes allow organisms to adapt to new niches
Copyright (c) by W. H. Freeman and Company
1.2 The molecules of life
The activities of cellular molecules are governed by the basic principles of chemistry
Cellular water, inorganic ions, and small organic molecules account for 75-80% of the living weight of a cell
Macromolecules (proteins, polysaccharides, DNA) account for the remainder
Copyright (c) by W. H. Freeman and Company
1.2 Cells are packed with molecules of various sizes
Figure 1-2
Copyright (c) by W. H. Freeman and Company
1.2 Examples of cellular macromolecules
Figure 1-3
Copyright (c) by W. H. Freeman and Company
1.3 Lineage tree of life on earth
Figure 1-5
Copyright (c) by W. H. Freeman and Company
1.3 The plasma membrane separates the cell from the environment
Figure 1-6
The fundamental structure of all cell membranes is the lipid bilayer
Various membrane proteins present in the different cell membranes give each membrane a specific
function
Copyright (c) by W. H. Freeman and Company
1.3 Prokaryotic cells
Single cell organisms Two main types: bacteria and archaea Relatively simple structure
Figure 1-7a
Copyright (c) by W. H. Freeman and Company
1.3 Eukaryotic cells
Single cell or multicellular organisms Plants and animals Structurally more complex: organelles, cytoskeleton
Figure 1-7b
Copyright (c) by W. H. Freeman and Company
Each chromosome is a single linear DNA molecule associated with proteins
The total DNA in the chromosomes of an organism is its genome
1.3 Eukaryotic DNA is packaged into chromosomes
Figure 1-8
Copyright (c) by W. H. Freeman and Company
1.4 The life cycle of cells
Cell division occurs when one cell, after a period of growth, divides to become two daughter cells
Most eukaryotic cells follow the cell cycle, an internal clock that determines the phases of cell growth and division
Progress through the cell cycle is controlled at checkpoints Cells may “leave” the cell cycle and differentiate to perform
specialized functions Cells may undergo programmed cell death as a way of
balancing cell growth or generating structures during development (apoptosis)
Copyright (c) by W. H. Freeman and Company
1.4 The eukaryotic cell cycle
Figure 1-9
Copyright (c) by W. H. Freeman and Company
1.5 Cells associate to form tissues
Tissues are composed of cells and extracellular matrix Tissues may form organs Rudimentary tissues and an overall body plan form early in
development due to a defined pattern of gene expression and the ability of cells to interact with other cells
Many animals share the same basic pattern of development, which reflects commonalities in molecular and cellular mechanisms controlling development
Copyright (c) by W. H. Freeman and Company
1.5 Multiple tissues combine to create this artery
Figure 1-11