1 Exploring Life

Characteristics of Life
• Organized
o An atom is the smallest unit of life
o We all come from a pre-existing cell
• Use outside sources for nourishment
o Get food such as meat and vegetables for energy
 Convert this food to glucose for energy for the cells
• Reproduce
o Offspring which have their ancestors traits
 Hereditary information in their gens
• Grow and develop
o Grow in relatively similar size and shape of ancestors
• Homeostatic
o Internal systems are organized to maintain with certain constraints such as body temperature
• Respond to stimuli
o If we hear a noise which is perceived as threatening our fight or flight response kicks in
• Adapts and has an evolutionary history
o All cells have come from pre-existing cells
o We adapt to changes in our environment to survive and maintain our species
“How has our ability to communicate defined us as a species? Sharing information with each other has allowed humans to rise to the top of the food chain and dominate our environments. But humans aren't the only species that can communicate. Organisms as simple as bacteria can communicate, a strategy that lets them cooperate to take down creatures millions of times their own size. Fish use pheromones to warn each other about predators and find mates. Chemicals are also an effective means of communicating on land, and they've allowed insects--some of nature's smallest and most unassuming animals--to become the most populous and prolific on earth. The ability to interact stretches back billions of years and has often been one of the primary factors in a species ability to evolve and survive.”
http://www.history.com/shows.do?action=detail&episodeId=361810

Human’s relationship to other animals
• There are three domains
o Eukarya
o Archaea
o Bacteria
• For the study of human biology we are focusing on the Eukarya group which includes animals, plants etc
o We all have membrane bounded nuclei
• Humans have a cultural heritage passed on from previous generations
• On a large scale we fit into a biosphere –which encompasses the earth

The process of Science
o The process of science is the way we have learned about the earth and ourselves
Scientific Study
o Includes scientific theory – theory is derived from scientific study using scientific method
o Scientific method is a logical and an organized way to develop a scientific theory
o The process of scientific method is used to test ideas by
 Observation – look at certain behaviors
 Hypothesis – suggest something happens in a certain way
 Experiments/observe – test hypothesis by creating studies of certain behaviors by random sampling. Observe test subjects behaving
• Controlled studies have random sampling and a variable such as a “placebo”
 Conclusions – by looking at information compiled through experiments and observation it can be concluded with relative accuracy that certain behaviors are exhibited within a degree of regularity. I would like to make an inference at this time that any conclusion can be reached if the experiments are biased. It is important to look at the way a sample is taken, who is observing, and how it is being observed
 Scientific Theory – is then showing us that it has been observed that over time certain behaviors result in certain situations and there is logical documentation showing how test was conducted. In the end it is up to us to determine whether or not the information is solid or not
• More often than not, information published in scientific journals are a primary source of information for our course
Science and Social Responsibility
o To me this is an ethical issue – on one hand we can use our discoveries for creative purposes such as producing less expensive energy or we can take this information and destroy such as the creation of the atom bomb
2 Chemistry of Life

Atoms to Molecules
Water and Living Things
• Water makes up 60-70% of our body weight
o The blood in our arteries is 92% water
• Blood transports oxygen and nutrients to our cells
• These nutrients (molecules) are used to produce energy
• Ions and molecules that interact with water are hydrophilic
• Ions and molecules that do not interact with water are hydrophobic
• Base solutions are known as base substances they either take up hydrogen or release hydrogen
Molecules of Life
The four categories of organic organelles are:
Carbohydrates
• Are stored and used for short term energy
o There are simple carbohydrates
o Complex carbohydrates
 Polysaccharides
• Starch and glycogen are stored forms of glucose
• Glycogen and glucose are stored in the liver which releases the glucose to keep our level at about 0.1%
Lipids
• Contain more energy per gram than other molecules
• Lipids or phospholipids form the cell membrane; they are the primary part of the cell membrane
• Fats and oils are used for long term energy storage
Proteins
• Support ligaments and skin
• Enzymes react together to speed up chemical reactions within the cells
• Some proteins allow molecules to enter and exit the cells
• Antibodies are proteins; they protect our immune system; they are part of homeostasis
• Hormones are proteins that which are messengers to the cells telling the cells what to do; they influence the metabolism of the cell
• Actin and myosin proteins aid in motion; they tell the muscles when to contract
Nucleic Acids
• DNA
o There are two types of nucleic acid RNA and DNA
o RNA conveys information to DNA and gives the DNA instruction as to the amino acid structure sequence
o DNA contains the bases ATGC is double-stranded the strands are held together by a hydrogen molecule
• RNA
o Is single stranded
o Is directly involved in protein synthesis
o RNA contains the bases AUGC (the U for Uracil replaces the thymine)
o ATP is the energy carrier in the cells
o After ATP breaks down it is rebuilt by ADP (P) an addition of phosphate this is the input energy required to rebuilt the ATP

3 Cell Structure and Function

What is a Cell? –The cell theory suggests that a cell is smallest unit of life that is alive which always comes from a pre-existing cell, and that all living things are made up of cells.
• Cell size – even though cells vary in size they all function by exchanging substances with their surroundings; the volume of the cell represents the needs of the cell. As the volume of the cell increases the size decreases; cell division restores the amount of surface area needed for exchange of materials
• We use microscopes to view the cell since they are so small; the microscopes used are the compound light microscope. The scanning electron microscope and the transmission electron microscope
Cell Organization
• Cells have an evolutionary history which suggests they evolved from the prokaryotic cell which has no nucleus
• Both eukaryotic and prokaryotic have a plasma membrane
• All cells contain cytoplasm and the cytoplasm contains organelles which are structures that perform specific functions in the cells
Plasma Membrane and how Substances Cross It
• The plasma membrane is the outer surface of the cell which regulates what goes in and out of the cell
• The plasma membrane is made of phospholipid bi-layer which proteins are set in
o The hydrophyllic head makes up the outer part of surface and the hydrophobic tails make up the interior
o Carbohydrate chains are attached to the inside surface while cytoskeletal filaments are attached to the inside
o The plasma membrane marks separates the inside of the cell from its outside environment
o It keeps the cell intact and allows only ions to enter and exit the cytoplasm, therefore the cell membrane is selectively permeable
o Diffusion is a passive way that molecules enter and exit the cell, they go from a higher concentration to a lower concentration
o Osmosis is the diffusion of water across the plasma membrane and a dissolved substance which can not pass by itself.
o Osmotic pressure is the force exerted on the membrane because of water moving from a higher to lower concentration
o Facilitated transport is when a dissolved substance is carried across the membrane by a protein carrier this is a passive transport as there is no energy needed
o Active transport requires ATP energy for transportation
• The parts of the cell are the:
o Nucleus which houses the nucleolus chromatin and is covered by the nuclear envelope. DNA and RNA are housed here also. rRNA is produced in the nucleolus where it joins with proteins to form subunits of ribosomes.
o Ribosomes
 are composed of proteins and rRNA; protein synthesis occurs at the ribosomes
 they also occur free thoughout the cytoplasm single or grouped which are called polyrobsomes
• The Endomembrane System consists of
o Two types of Endoplasmic reticulum (ER)
 Rough ER – which synthesizes proteins and packages them in vesicles
 Smooth ER – which synthesizes lipids and has other functions depending on the cell type
o The Golgi Apparatus – modifies lipids and proteins from the ER then packs and stores them in vesicles.
o Lysosomes break down cell parts and substances which enter by vesicles using digestive enzymes
o There are secretory vesicles and transport vesicles
 The transport vesicles carry lipids and proteins to the Golgi Apparatus
 The secretory vesicles secrete proteins through the plasma membrane
The Cytoskeleton and Cell Movement
• Cytoskeleton is a crisscross of protein fibers which maintains the cells shape and attaches organelles or aids in their movement
o Microtubules in the cytoskeleton assist movement of chromosomes during cell division
o Cilia and Flagella aid in movement such as the ciliated cells in our respiratory system sweep along debris to keep our lungs clear
Mitochondria and Cellular Metabolism
• Mitochondria is called the source of power for the cell; it produces energy by converting the energy of glucose products into ATP energy
• The process of producing ATP is called cell respiration
o Mitochondria takes up oxygen and gives off carbon dioxide
o Mitochondria has a double layered outside membrane and a single folded layered inside membrane which is called the cristae. The cristae contains enzymes
• Cellular respiration is a very important part of the metabolism and chemical reactions in the cell
o Blood takes glucose and oxygen to the cell then cellular respiration breaks down glucose to carbon dioxide and water begins. Glycoysis, citric acid cycle and electron transport chain allow the energy in a glucose molecule to slowly release so that the ATP energy can be produced little by little. This process produces heat when ATP is used. The breakdown of ATP produces ADP + P. ADP is a nucleotide with two phosphate groups which allow another phosphate group then become ATP
4 Organization and Regulation of Body Systems

Tissue has three components: ground substance, specialized cells and protein fibers. The protein fibers are made of collagen for flexibility and strength
Types of tissue
• Fibrous connective tissue
o Loose – found in the lungs arteries and bladder; this tissue allows those organs to expand
 Adipose is a type of loose connective tissue which allow cells to enlarge and store fat
o Dense – knitted closely together and have specific functions; this tissue is found in the tendons and ligaments
• Supportive Connective tissue
o Cartilage – there are three types
 Hyaline found in he nose and end of long bones, and respiratory walls
 Elastic cartilage found around the outer ear
 Fibro cartilage is found in body parts that require strength against tension and pressure such as the disks in our backbone
o Bone – is the most rigid connective tissue and has a hard matrix
 There are two types of bone
• Compact bone – runs along the long bone
• Spongy bone – appears as open lattice looking
• Fluid connective tissue
o Blood – can be classified as connective tissue or some suggest there is a separate category called vascular tissue
 Consists of plasma and other formed elements
 Transports nutrients and oxygen to the tissue fluid which bathes the cells
 Removes carbon dioxide and other waste
 Helps control body temperature by controlling body heat
 Red blood cells (eryrthrocytes) are small disk shaped cells with no nuclei
 White blood cells(leukocytes) are larger and have a nucleus; they fight infection
• Some white blood cells surround the infection while other white blood cells produce antibodies
 Platelets – are fragmented pieces of larger cells and are only found in bone marrow
• Platelets help repair broken blood vessels by clotting
o Lymph - fluid connective tissue which is derived from fluid which contains white blood cells
Muscular Tissue Moves the Body
• Muscular tissue cells are muscle fiber which contains protein filaments called actin and mysin
• There are three types of vertebrate tissue
o Skeletal – multiple nuclei, voluntary, cylindrical and long; it runs the length of our long bones attached to tendons which contract and move our body parts
o Smooth - single nucleus, involuntary, found in the walls of intestine, bladder, blood vessels and other internal organs; they can remain contracted for a longer period of time. When smooth tissue contracts in the blood vessels this may cause hypertension
o Cardiac - single nucleus, involuntary, is found in the heart; contracts to pump the blood. The cardiac tissue is combined with both skeletal and smooth muscle.
Nervous Tissue Communicate
• Nervous tissue consists of nerve cells (neurons) and neuralgia (cells which support & feed neurons)
o Neurons have three parts
 Dendrites - receives the signals from sensory receptors
 Cell Body – contains cytoplasm and nucleus
 Axon – carries the nerve impulses from cell body to the synapse
• Long axons are covered with myelin a white fatty substance
o Fibrous tissue is a component of the matrix; outside the spinal cord and brain fibers are bound by connective tissue to form nerves. These can regenerate but not the ones inside an organ
o Nerves regenerate outside because new neuralgia called Schwann cells forma pathway for axons to reach the muscle
Epithelial Tissue Protects our skin protects our internal organs
• There are five type of epithelial tissue
o Simple epithelia – single layer of flat shaped cells which line the walls of lungs sacs and blood vessels; this is where the exchange of oxygen and carbon dioxide takes place; also nutrients are exchanged for waste here
o Pseudo stratified Columnar epithelia - this lines the walls of the windpipe and trachea; it traps foreign substance and they are carried out by mucous. Inflammation here causes bronchitis
o Transitional- this changes in response to tension
o Stratified – this lines the cervix (where a pap can determine cancer), the mouth, nose esophagus and anal canal
o Glandular – glands can contain many cells you find glandular epithelia tissue in the sweat glands, mammary glands. Endocrine glands have no ducts and can be found in the pancreas, thyroid and pituitary. These glands secrete hormones that are transported into the bloodstream
• Cell Junctions – Muscle and nerves are connected by cell junctions
o Tight junctions – fasteners between cells
o Adhesion junctions – allows cells to bend and stretch
o Gap junctions – allow molecules to go between cells
• Integumentary Systems are specific tissue with specific functions
o For example an organ system such as skin has several organs such as hair, glands, nails.
o Skin is the most prominent system because it covers our bodies
 Regions of the skin include epidermis, dermis and subcutaneous layer
• Epidermis is made up of squamous epithelium
• Dermis is the dense fibrous layer beneath the epidermis
• Subcutaneous layer is beneath the dermis but is not considered part of the skin. This layer is comprised of loose connective tissue. This is where we store fat
• Organ Systems
o Organs make up organ systems; our organs to ensure homeostasis
 Integumentary system is comprised of skin, hair nails, muscles that move hair, glands, blood vessels and nerves
• Main functions are to control body temperature, receive sensory input
 Cardiovascular system circulates the blood, the blood distributes heat to the body , transports oxygen and removes carbon dioxide
 Lymphatic and immune systems consist of spleen lymph nodes; this system accumulates any surplus tissue fluid and also absorbs fat
 Digestive system contains the moth esophagus, stomach, small intestine and large intestine. There are other organs that are associated with the digestive system to help it do its job such as the teeth, tongue, etc. Our digestive system makes use of materials from our environment such as salad or bacon to keep us alive
 Respiratory system is made up of our lungs and the tubes that supply our bodies with the oxygen that is needed for the blood to do its work
 Urinary system is comprised of the kidney, bladder and tubes that carry urine. This system helps our bodies get rid of waste
 Skeletal system is our framework. The bones here move and protect our bodies.
 Muscular system moves our bodies, makes our heart beat and produces heat
 Nervous system consists of brain, spinal cord and associated nerves. These nerves carry the nerve impulses which help us to respond to danger or pleasant situations
 Endocrine system carries the chemical messengers called hormones which regulate cell metabolism and other body systems
 Reproductive systems help us to carry on our heritage by reproducing offspring.
o Body Cavities
 There are two main body cavities
• Dorsal- brain and spinal cord
• Ventral – thoracic cavity, abdominal cavity and the pelvic cavity
• Homeostasis
o This is a term used to describe our organ systems way of maintaining an equilibrium in our internal environment
 Negative feedback happens when a sensor perceives a change in the environment that will upset homeostasis, it will regulate to bring things back into order
 Positive feedback is a method of bringing about an elevated change by methods such as sensory perception that immediate action is necessary.