Biology 129Human Biology

Richard R. Almon Ph.DProfessorDepartments of Biological Sciences,Pharmaceutical Sciences and The NY State Center of Excellence in Bioinformatics and Life Scienceshttp://www.biologicalsciences.buffalo.edu/http://www.biology.buffalo.edu/courses/bio129/Bio129_2008/index.html

Chapter 1: Overview

You are living because….

You die because…..

Potential Energy

• Car at top of hill

• Shaken oil and vinegar salad dressing

• Fire wood

Molecules are formed by the interaction of atoms

More molecules

Fatty acid

DNA

Coupling reactions

• Favorable: releases energy, more disorder

• Unfavorable: requires input of energy, more order

Molecules and atoms: the building blocks of life

• Two sources of materials– Imports: Salts (atoms), small molecules (sugars,

amino acids, small fats, nucleotides, vitamins, water)

– Made by the body: such as some sugars, some amino acids, some fats, nucleotides, vitamins, plus big complex proteins (connected amino acids), carbohydrates (connected sugars), nucleic acids (connected nucleotides), lots of different fats

Oil and water: two different environments

An environment of electrical charge

An environment of no charge

Compartments• Fighting the drive towards

equilibrium is life

• Equilibrium is dead

New life

• Sharing around genetic material

• Reproduction

• They don’t have to go together

Single cell forms of life

• Life span = the life span of a single cell

• Rapid generation times

• Rapid evolution (eg antibiotic resistance)

Multicellular organisms

• Specialization of cells• Increased complexity• Life span is no longer

the life span of a cell

A society of cells

A society is a grouping of individuals characterized by patterns of relationships between these individuals

Wikipedia

Cells: Specialized individuals in the society

• There exist types of specialized groups of cells: liver, heart, lung, muscle, kidney, skin etc.

• These groups carry out duties necessary to the functioning of the society (the body).

• There are common things all cells must do to carry out their role in society

• There are special things that cells do to accomplish their special duties in the society

Communications

• Each type of cell in the society has a specialized function that makes the community work.

• A society works only because the specialized individuals talk to each other.

• Specialized cells talk to each other with chemical signals.

• The primary purpose of all of this talking is to keep you alive.

You started as one cell

• Genes and their packaging:– The directions for how and when to make

particular proteins– Proteins: Very large molecules made up of

smaller molecules called amino acids– Proteins are the ability of a cell to do something– No cell can make (express) all proteins: The

difference between different types of cells is the proteins they make.

Stem cells

Nature/Nurture

• Genetics is potential (Nature)

• Environment acts on this potential (Nurture)

• Epigenetics and development (Fetal programming)

Variations on a theme

Variations

Different populations

An individual is not constant

The response to change

Keeping you alive

• Maintaining the quality of the water environment of the body (the blood)

• Each specialized group of cells lives in a unique water environment extracted from the blood

• Some groups of specialized cells are more important than others

The Rule: water follows salt

Keeping you alive

Bringing in enough “low energy” molecules: carbohydrates (sugar), lipids (fat) and proteins (amino acids) to generate enough “high energy” molecules = ATP, which requires bringing in enough oxygen

Getting rid of the waste produced by this process

The Central Nervous System: who you are

The most important group of specialized cells

Brain

Spinal cord

The Brain: The priority

1. The Brain controls everything

2. The Brain is at the center of all protective mechanisms

3. The Brain is composed of nerve cells and helper cells

4. Nerve cells are never replaced

5. The Brain is most vulnerable to damage

Controlling the Body

• The Central Nervous System (brain and spinal cord) controls the body

• Information in, information out

• What is information?

Information

• Information in: everything is information to the brain eg.– Amount of sugar in the blood– The temperature of the blood– Blood pressure

Information Out: Patterns of chemical

Messages: Neurotransmitters and hormones