A look at Human Biology

• Human Beings are related structurally and physically to animals and all living things.

• In order to understand ourselves better we study every living thing from viruses, bacteria to mice and monkeys.

• Science gives a best guess as to what is going on in our bodies.

What is homeostasis

• The adjustments that every living organism must do to preserve their internal environment.

Modes of homeostatic control

• Negative feedback– Thermoregulation

– At a setpoint the effector is turned of

• Positive feedback– Birth

– Only removal of the stimulus reduces the signal

Topic 2 the chemistry of life

It’s the small things that make life good. Nick Kapp 2000

The Natural consists of Matter and Energy

• Matter anything that has mass and occupies space.

• Energy: the capacity to do work

• Which of these can be recycled?

The 4 most abundant elements of life

• Elements, are the fundamental (smallest) particles of matter.

– Nitrogen

– Oxygen

– Carbon

– Hydrogen

Draw the parts of an element• Electron (negative charge)• Neutron (no charge but has mass)• Proton (positive charge)

• Energy holds these together

Other Items

• The most stable forms of matter have the lowest amount of energy.

• Free radicals (are lacking electrons)

• Antioxidants: (counter free radicals)

The human body is 2/3 water

• Hydrophobic

• Hydrophilic

• Water hating

• Water loving (soluble)

How do different compounds react in water?

• List some?

Hydrogen ions play an important role in life

• Molecules that donate a hydrogen ion (H+) are called acids.

• Molecules that accept hydrogen ions are called bases.

• The hydrogen ion concentration of a solution is called the pH.

• Buffers minimize changes in ph.

The molecules of life:organic molecules

• Monomer: one of something.

• Dimer: two of something.

• Polymer: many of something.

4 types of organic molecules make up the human body

2 or more atoms together make a molecule

You are what you eat

Estrogen (Estradiol)

Glucosewater

Carbohydrates: quick energy

• Monomers are sugar (glucose)– saccaride = sugar

• Oligosaccaride- sucrose or dextrins made of a few monomers

• Polysaccharides- starch, fiber

• CH2O

Lipids

• Oils, fats, waxes, sterols

• Energy storage, insulation, water proofing

• Hormones

• Hardening of membranes

• CHO

Amino Acids, Proteins

• AA is the monomer, Polymer is protein• Enzymes- catalysts that speed up reactions• Are sensitive to temperature, pressure, pH• Structural unit of hair, nails, cells, bone, cartilage

and skin

• Protease (All@ the detergent with protein)

• NOCH (some S)

Proteins are enzymes

• And how do enzymes work?

Nucleic acids

• DNA: Information storage, double stranded.

• RNA: Information transfer.

• ATP: Energy intermediates.

• Enzyme cofactors (NADH2).

• NOCH

SummaryYou are what you eat. Your body requires that you consume all of its

subunits in your diet, or you use some of your energy to make those

subunits.

Bad bricks make a bad house

Topic 3: The Cell

The smallest unit of life it the cell.

Can you think of anything smaller?

What is alive?

The cell theory of life

• All organisms are composed of 1 or more cells.

• The cell is the smallest functional unit of life.

• Cells only come from other cells.• Cells maintain homeostasis.

– Cytology is the study of the structure and function of a cell.

Two types of cells

• Eukaryotic– Have internal

membrane bound organelles

– Usually larger

– Usually individuals are much more complex

– Most things you can see

• Prokaryotic– No internal membrane

bound organelles

– Individuals are simple

– Bacteria, most are too small to see, most do not cause disease

Physical properties that we will use all semester long.

Diffusion

• Movement of molecules down a concentration gradient

OsmosisMovement of water across a semi

permeable membrane

Tonicity

Transport Mechanisms

• Passive transport: works by diffusion.

• Active transport: energy required to move molecules across the membrane.

• Endocytosis: membrane wrap around materials that go into cells.

• Exocytosis: membrane wrap around materials that go out the cells.

Fig 2.8

Parts of the cell that you need to know

• Cell membrane• Cytosol• Cytoskeleton• Microvilli• Cilia• Centrioles• Ribosomes• Endoplasmic reticulum

• Lysosome• Mitochondria• Nucleus• http://

www.probes.com/handbook/figures/1201.html

• page 65

• link

A typical eukaryotic cell

The cell membrane

• Function: gateway to life, the portals of the cell.

• Structure:– Phospholipids– Hydrophobic– Bilayer– Gateway proteins are embedded like a mosaic

Fig 2.4

Fluid Mosaic Model

Metabolism

• The controlled capacity to acquire energy, break apart and eliminate substances.– Biosynthetic pathway: anabolism making molecules

– Degradative pathways: catabolism, breaking molecules apart and harvesting the energy

• The sum of the chemical events that occur in the body– Substrate and Product

Enzymes

• Serve as catalysts, and speed up reactions.• A series of enzymes together perform the

metabolic processes– Make reactions happen faster– Are reused– Are reversible– Are specific– Use cofactors (in order to function)

Enzymes are proteins so are susceptible to

• Heat

• Cold

• pH

• Presence of cofactors

Summary of energy harvests

• Aerobic reactions.– Glucose and Oxygen are combined to make

Carbon Dioxide and energy is transferred to ATP (roughly 34) In mitochondria

• Anaerobic reactions– Without Oxygen Glucose is converted to

Lactose and energy is transferred to ATP (only2)

Alternative energy sources

• While the body is set up to harvest energy from glucose, it can also use other molecules.

The Electron Transport System

• On the inner membrane of the Mitochondria

• Hydrogen ions are pumped to the space in-between the membranes.

• Production of ATP is tied to the movement of these ions back into the cell.

Pick your organelles

• Take 5 minutes in groups and research an organelle

• Draw a picture and write it out on the board.