chapter01 the dynamic cell

Copyright (c) by W. H. Freeman and Company

Chapter 1

The Dynamic Cell


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


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


1.2 Cells are packed with molecules of various sizes

Figure 1-2


1.2 Examples of cellular macromolecules

Figure 1-3


1.3 Lineage tree of life on earth

Figure 1-5


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


1.3 Prokaryotic cells

Single cell organisms Two main types: bacteria and archaea Relatively simple structure

Figure 1-7a


1.3 Eukaryotic cells

Single cell or multicellular organisms Plants and animals Structurally more complex: organelles, cytoskeleton

Figure 1-7b


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


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)


1.4 The eukaryotic cell cycle

Figure 1-9


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


1.5 Multiple tissues combine to create this artery

Figure 1-11

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