Transcript Levels of Organization

Levels of Organization
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Molecule
Cell
Tissue
Organ
Organ system
Organism
Population
Community
Ecosystem
Biosphere
Molecules of Life
Type
Function
Protein
Identity
Enyzme
Hormone
Energy
Energy Storage
Information
Storage
Carbohydrates
Nucleic Acids
Lipids
Examples
Membrane proteins
Lipase
Insulin
Glucose
Glycogen
DNA
RNA
Energy Storage Fat
Basic Metabolism of Life
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Photosynthesis
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Capturing of sunlight and carbon dioxide by plants to
make sugar and complex carbohydrates
Plants provide the energy for the rest of life
Oxygen is a by-product of this process
Respiration
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Releasing of chemical (ie. Sugar) energy by the
chemical process of oxidation
Carbon dioxide is released in this process
Two Major Types of Cells
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Eukaryotic Cells
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Nucleus
Chromosomes
Mitochondria
Golgi Bodies
Endoplasmic
Reticulum
Examples include
our body cells,
amoeba, plant cells
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Prokaryotic Cells
No nucleus, bare,
circular DNA
 No organelles
 Very small (0.1 to
0.01 size of
Eukaryotic cells
 Examples: bacteria
(Tuberculosis)
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Four Types of Human Tissue
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Epithelial – coverings
Connective – bind, support, insulate
Muscle – smooth, cardiac and skeletal
Nervous – detection, integration, action
Infectious Disease
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Prion
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Virus
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Prokaryotic cells
Example: Mycobacterium tuberculosis
Protozoa
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DNA or RNA packages with protein
Examples: colds, influenza, HIV
Bacteria
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Misfolded proteins, ex. “Mad cow disease”
Single-celled, eukaryotic invaders
Examples: Malarial Plasmodium, Giardia
Multicellular Parasites
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Examples: worms, fungi (ringworm, athlete’s foot)
Integumentary
System
Muscular
System
Skeletal
System
Nervous
System
Endocrine
System
Circulatory
System
Lymphatic
System
Respiratory
System
Digestive
System
Urinary
System
Reproduction
System
Integumetary System
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Skin – complex system of tissues
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Epidermis and dermis
Sweat glands – homiothermic balance
Oil glands – lubrication for flexibility
Sensory cells – Stimulus
Hair and Nails – derived from epidermis
Skeletal System
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Bones – calcium-rich, mineralized matrix
Cells inside of bone
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Blood
Immune system
Bone Remodeling
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Childhood growth
Reabsorbtion - osteoporosis
Muscular System
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Three types of Muscle Tissue
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Cardiac – Heart Muscle
Smooth – Intestines, arteries, etc.
Skeletal – attached to bone (ligaments) and
other muscles (tendons)
All use a protein and ATP mechanism for
contraction
Nervous System
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Central Nervous System
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Brain – major integrator
Spinal Cord – major conductive pathway
Peripheral Nervous System
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Somatic (motor and sensory)
Autonomic
Sympathetic – “fight or flight” response, short
term stress
 Parasympathetic – relaxation response
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Nervous System
Nervous System
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Sensory Nerve cells
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Motor Nerve cells
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Mechanoreceptors, thermoreceptors, pain
receptors, chemoreceptors, photoreceptors
Connect from the CNS to the muscle
May be under conscious control (via brain) or
reflex control (spinal chord)
Integrative Cells
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Interneurons and brain cells
Nervous System
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The “limbic” system – connections in the
midbrain, generates emotions and
communicates to the …
Hypothalamus – a structure of the brain
that greatly influences the …
Pituatary Glands – two structures (anterior
and posterior) control much of the
hormonal production of the body
Endocrine System
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Hormonal control of the body
Works with nervous system for short and
long term control
Major glands
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Hypothalamus/pituitary
Thyroid
Adrenals
Pancreas (insulin and glucagon)
Gonads (ovaries and testes)
Cell, especially
muscle, takes up
glucose and uses it
or converts it to
glycogen.
insulin
Beta cells of pancreas
release insulin into blood.
Stimulus:
Glucose is
absorbed
following a meal.
Blood glucose levels increase
to a set point; stimulus calling
for glucagon diminishes.
Liver converts glycogen
to glucose, stops
synthesizing glycogen.
Liver converts glucose
to glycogen, fats, proteins.
Blood glucose levels decline
to a set point; stimulus calling
for insulin diminishes.
Alpha cells of
pancreas release
glucagon into blood.
glucagon
Stimulus:
Cells use or store
glucose between
meals.
Digestive System
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Types of enzymes
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Proteinases – break down protein
Lipases – break down lipids
Carbohydrases (ex. Amylase) – break down
carbohydrates
Nucleases – break down nucleic acids
Bile salts
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Emulsify lipids (fats and oils)
Digestive System
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Mechanically prepares food for digestion
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Mouth with teeth – mechanical processing
Stomach – mechanical processing, few
enzymes
Chemical degradation (digestion)
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Pancreatic enzymes (all classes)
Bile salts from liver
Some enzymes from saliva and stomach
Digestive System - Nutrition
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Calories (for energy, mostly in the form of
carbohydrates and lipids)
Vitamins (cannot make by ourselves)
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Vitamin A – eyesight
Vitamin C – various functions
Vitamin D – bone growth
Vitamin E – cell membrane
Essential Amino Acids/ Fatty acids
Minerals (Iron, Calcium, Zinc, etc.)
Respiratory System
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Essential for Gas exchange
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Driven by partial pressure of gasses
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Removal by exhalation of carbon dioxide
Absorption of oxygen
Alveoli – high carbon dioxide, low oxygen
Atmosphere – low carbon dioxide, high
oxygen
Major route of infection and trouble
Circulatory System
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Heart – the double pump
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Arteries
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Systemic circulation
Pulmonary circulation
Conduit for blood moving away from heart
Are musculated by smooth muscles
Veins
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Conduit for blood moving to the heart
Have one-way valves, rely on skeletal muscle
Lymphatic System
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Bathes tissues in non-cellular fluid (lymph)
Collects lymph and returns it to the
circulatory system
Plays an important role in the immune
system
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Lymph glands – tonsils, etc.
Thymus gland – home of T-cells
Urinary System
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Maintain water and mineral balance
Major structures
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Kidney
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Nephron is the functional structure
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filtration , absorption, and secretion
Urinary Bladder
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Collects and holds urine for conscious elimination
Defense – Non-specific Response
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Phagocytes
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Inflammation
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White blood cells (Leucocytes) respond quickly to
injury or invasion
Redness, swelling, warmth and pain
Mast cells release histamine (responsible for many of
the symptoms of inflammation)
Allergies
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Inflammatory response to “normal” substances
Defense – Immune Response
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Antibody Mediated Response
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Cell Mediated Response
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Triggered by exposure to antigen
Effector B-cells produce antibodies
Memory B-cells prepare for secondary
response
Effector Cytotoxic T cells result
Both Types rely on Helper T-cells
ANTIBODY-MEDIATED
IMMUNE RESPONSE
antigen
antigen
CELL-MEDIATED
IMMUNE RESPONSE
naïve helper T cell
naïve B cell
antigen-presenting cell
naïve cytotoxic T cell
effector B cell
activated
helper
T cell
antibody molecules
effector
cytotoxic
T cell
infected body
cell
Reproductive System
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Under hormonal control
Both genders produce gametes by meiosis
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Ovaries – eggs are produced by a complex cycle
controlled by hormones
Testes – sperm are produced continuously
Meiosis insures that the gametes have only half
the number of adult chromosomes (haploid cells)
Fertilization (egg and sperm fusion) restores the
chromosome number to the adult count (diploid)
Genetics
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DNA directs the synthesis of proteins
DNA is found in the chromosomes
Chromosomes are found in the nucleus
Each somatic (body) cell has two copies of
each chromosome
Humans have 23 pairs of chromosomes
Human somatic cells have 46
chromosomes
Genetics
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Gametes have 1 copy of each chromosome
Fertilization makes new combinations by
fusing eggs and sperm
Brand new genes come from mutations of
old genes
Some genes are beneficial, some are
deleterious, most depend on the
environment
Sickle Cell Anemia Illustrates…
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New genes from old through mutation
Direct relation between DNA and protein
Relation between a changed protein and the
many changes that it brings about
Relation between a gene and the
environment in which it is found
Natural Selection in humans as it is
disappearing in African-americans
Evolutionary Theory and Biology
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The cornerstone of modern biology is
evolutionary theory
For example, it predicts and explains…
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Antibiotic resistance
Genetic diseases and defects
The fossil record
Genetic engineering
Tooth, back, hip and knee problems
Etc. etc.
Ecology
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Ecosystems have …
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A flow of energy through them (sunlight to
heat)
Cycling of nutrients (water, carbon cycle)
Interacting organisms (food webs)
Internal balance mechanisms that can break
down, leading to ecosystem collapse
Human Biology
Although this class focused on humans and
used the human body as an example of an
integrated organism, we should remember
that this is a human-centered view.
Other views are possible, for example, …
A chicken is just an egg’s way of producing
more eggs.