Download The Big Picture

Name: _________________________________________________Date:______________
The Big Picture: A Review of Biology
Chemistry of Life
Organic Compounds
A compound is a combination of 2 or more atoms
An organic compound is a compound that contains carbon atoms
An inorganic compound is a compound with no combination of carbon atoms ex. Water
Six most important elements essential to life: Carbon, Hydrogen, Nitrogen, Oxygen,
Phosphorus, Sulfur (CHNOPS)
The Four Types of Organic Compounds (The Molecules of Life) made from the 6 elements:
Carbohydrates: Sugars used for short term energy – major source of energy
Lipids: Fats and oils used for long term energy
Proteins: Made up of amino acids; used for construction materials and chemical reactions in
the body
o Enzymes: Special types of proteins that speed up chemical reactions in the body but
are not changed by the reactions
Nucleic acids: DNA genetic information, RNA – protein synthesis, ATP – energy for cells
Atom – the smallest unit of matter that cannot be broken down by chemical means.
Molecule – a group of atoms that are held together by chemical bonds.
Element – substance made up of one type of atom; having the same atomic number.
Cell Biology
Cells
A cell is the smallest unit that is alive and can carry on all the processes of life
Cells make up organisms (living things)
o Unicellular organisms are made up of 1 cell
o Multicellular organisms are made up of many cells
Cells contain organelles, which are specialized compartments that carry out a specific function
Cell membrane is made up of a phospholipid bilayer: Phosphate heads and lipid tails.
o Phosphate heads are polar, attracted to water
o Lipid tails are non-polar, repel water
Only certain things pass through the cell membrane such as other lipids. Ions and most polar
molecules are repelled by the lipid bilayer.
Materials need to be transported through the cell membrane by:
o Passive Transportation – no energy expended by cell
o or Active Transportation – energy is expended by cell
Passive Transport – No energy is used to transport substances across the cell’s membrane.
o
Diffusion- movement of substances from an area of high concentration to an area of
lower concentration of that substance through a semi permeable membrane (cell membrane)
o Facilitated Diffusion – the movement of substances through the cell membrane using
transport proteins, channel and transport proteins, that help substances diffuse through
the cell membrane.
o Osmosis – the movement of water through the semi permeable membrane from an area
of high concentration of water to an area of low concentration of water.
o Free water molecules moving down their concentration gradient .
o Solutions can be
 Hypertonic – high solute concentration – cell shrinks by losing water
 Hypotonic – lower concentration of solutes than the cell’s cytoplasm, cell
expands
 Isotonic – has the same solute concentration as the cell’s cytoplasm, cell stays
the same size.
2
Active Transport – Energy is used to move substances against their concentration gradient
across the cell membrane.
o Pumps- Sodium Potassium Pump – moves sodium out and potassium into the cell.
o Vesicles –movement of large substances across the cell membrane in vesicles,
membrane bound sacs, which have been created by the cell membrane.
 Endocytosis –moving material into the cell
 Exocytosis – moving material out of the cell
Cell Communication – cells communicate by sending chemical signals to other cells
o Receptor proteins receive the signal and cause responses.
Types of cells
o Eukaryotic cells contain a nucleus, such as animal and plant cells
o Prokaryotic cells contain no nucleus, such as bacteria
Animal Cells (Eukaryotic Cell)
Usually round
Organelles include :
o nucleus: controls cell activities
o cell membrane: controls what enters and leaves the cell and also protects the cell
o endoplasmic reticulum (ER): passageway/tunnels for compounds and proteins to move
through the cell
o Golgi body: processes, stores and packages protein
o Ribosomes: make proteins
o Mitochondria: makes energy for the cell (powerhouse of the cell)
o Lysosome: contains enzymes that digest waste and old organelles
o Cytoplasm: fills the empty space of the cell
o Vacuole: stores food, water, and waste
o Centrioles: assists in cell division and is only found in animal, not plant, cells
Plant Cells (Eukaryotic Cell)
Usually square
Organelles include:
o All organelles that an animal cell has plus Chloroplasts, Cell Wall and Central
Vacuole
o Chloroplast: Traps sunlight to make food for the plant
o Cell wall: Protects the cell
o Central Vacuole – large central storage for water, wastes and nutrients
Bacterial cells (Prokaryotic Cell)
Smaller and simpler than plant or animal cells
Bacteria are unicellular
No nucleus
Have a single closed loop of DNA, cell wall, cell membrane, cytoplasm and ribosomes
Some have a capsule (shell for protection), pili (short hair like structures to hold onto host
cells), and flagella (whip like structure for movement)
Cell membrane
Made up of molecules called phospholipids
Phospholipid bilayer is the 2 layers of phospholipids that make up the cell membrane
Cell membrane is fluid, which means that it is constantly flowing and moving over the cell
3
Cell membrane is selectively permeable, which means that it allows small compounds, but
not large ones, to pass right through
There are different ways that materials are transported across the cell membrane
o Passive transport: requires no energy
 Diffusion: compounds move from high to low concentration
 Osmosis: diffusion of water
 Facilitated Diffusion: protein carriers, no energy (ATP) used
o Active transport: requires energy
 Endocytosis: large compound are brought into the cell
 Exocytosis: large compounds are exported out of the cell
Types of solutions
o Hypotonic solutions cause water to move into the cell so the cell swells up
o Hypertonic solutions cause water to move out of the cell so the cell shrivels up
o Isotonic solutions cause no net movement of water into or out of the cell
Photosynthesis
Process by which organisms use energy from sunlight to make their own food (glucose)
Glucose is a simple sugar - monosaccharide
Photosynthesis occurs in the chloroplasts of plant cells and some bacteria
Chloroplasts have a green pigment called chlorophyll
Steps of photosynthesis
o 1. Light reaction: chlorophyll in the chloroplasts absorbs sunlight
o 2. Dark reaction: The energy from the sunlight is used to make glucose
Light energy is completely changed into chemical energy (glucose)
Chemical equation for photosynthesis
6CO2 + 6H2O + light energy  C6H12O6 + O2
carbon dioxide water in the presence of chlorophyll
glucose
oxygen
Cellular Respiration
Process that breaks down glucose in order to make energy for an organism
ATP: compound that stores energy in an organism
Occurs in the mitochondria of the cell
Two types of cellular respiration
o Aerobic respiration: requires oxygen to occur
 Mostly happens in animals and plants
There are 3 steps in aerobic respiration
Step 1 is glycolysis: glucose is cut in half
Step 2 - citric acid cycle: glucose halves
Step 3 electron transport chain: electrons combine with oxygen and are
used to make ATP
 Chemical equation for cellular respiration
C6H12O6 + O2  6CO2 + 6H2O + ATP energy
glucose
oxygen
carbon dioxide
water
ATP energy
 Aerobic respiration is the opposite reaction of photosynthesis
o Anaerobic respiration: does not require oxygen to occur
 Mostly happens in bacteria and yeast
 Also called fermentation –
Two types: Alcoholic fermentation and Lactic Acid fermentation
 Makes less ATP than aerobic respiration
4
Anatomy and Physiology
The Human Body Systems
Body Organization
Embryonic stem cells can become more than one type of cell.
Cells, tissues, organs, organ systems.
The human body contains four types of tissues:
o Epithelial Tissue – covering of organs
o Nervous Tissue – made of neurons, nerve cells.
o Connective Tissue – bones, blood, ligaments, tendons
o Muscle Tissue –
o Smooth muscle – found in intestines and bladder,
o Cardiac muscle – found only in the heart
o Skeletal muscle- muscle connected to bones
Tissues that work together form organs.
Organs that work together form organ systems.
The body maintains homeostasis, a steady internal environment.
The Skeletal System
The five important functions of the skeletal system are support, protection, movement, mineral
storage, and blood cell formation.
The structure of a typical bone includes the periosteum, compact bone, spongy bone, and bone
marrow.
Movable joints are made up of bone, cartilage, and ligaments.
o Saddle joint- thumb
o Pivot joint – neck
o Ball and Socket joint- hip
o Hinge joint- knee
o Gliding joint - foot
The Muscular System
The human body contains skeletal, smooth, and cardiac muscle.
Muscles switch between two processes to produce ATP.
Skeletal muscle is made of muscle fibers, myofibrils, and sarcomeres.
Actin filaments sliding inward along myosin filaments cause muscle contraction.
Exercise affects strength, speed, endurance, fatigue, injury, and atrophy in muscles.
The Integumentary System
The structure of skin includes the epidermis, dermis, and subcutaneous layer.
The skin protects the body and helps regulate body temperature.
Hair and nails are made by cells in the skin.
Melanin - dark pigment
Keratin – protein that protects the skin, gives it texture and makes it waterproof.
Skin disorders can be genetic, caused by infections, or the result of changes in the body.
The Cardiovascular System
The cardiovascular system carries nutrients, oxygen, hormones, and wastes throughout the
body and distributes heat to maintain homeostasis.
The structure of the heart chambers is related to their function.
5
o The atria are thin walled because they pump blood just to the ventricles.
o The ventricles are thick walled because they pump blood to either the lungs or the rest
of the body.
The structure of blood vessels relates to their function.
o Arteries have thick, muscular walls to withstand the force of the pumped blood.
o Capillaries have thin walls to allow the exchange of gases and nutrients.
o Veins have valves that stop blood from flowing backward.
The key components of human blood are
o plasma,
o red blood cells,
o white blood cells, and
o platelets.
The lymphatic system works with the cardiovascular system by collecting fluids that leak out
of capillaries and returning those fluids to the cardiovascular system.
Cardiovascular Health
The four main cardiovascular diseases are high blood pressure, arteriosclerosis, heart attack,
and stroke.
The most important ways to prevent cardiovascular disease are to maintain a healthy diet,
exercise regularly, and avoid tobacco and alcohol use.
The Respiratory System
Air enters the nasal passages, and then flows through the pharynx, the larynx, the trachea, the
bronchial tubes, and finally the bronchioles into the alveoli of the lungs.
When the diaphragm and rib muscles contract, the chest cavity expands and air rushes in.
When these muscles relax, the chest cavity returns to a resting position and air rushes out.
Oxygen is transported bound to hemoglobin (protein) inside red blood cells
Most carbon dioxide is transported as bicarbonate ions in the plasma.
Six common diseases of the respiratory system are asthma, bronchitis, pneumonia,
tuberculosis, emphysema, and lung cancer.
Nutrition
Your body needs energy to breathe, pump blood, and grow. The more active you are, the more
Calories you burn to release energy.
Carbohydrates, Proteins, and Fats provide most of the energy and building materials for the
body.
Water, vitamins and minerals contribute to many functions, such as regulating chemical
reactions that release energy.
Good nutrition must be balanced with regular physical activity to maintain a healthy body.
Digestion
The digestive system takes in food, breaks it down, both chemically and mechanically, into
molecules that the body can use, and gets rid of undigested molecules and waste.
The mouth, esophagus, and stomach begin the process of digestion by breaking food into
small molecules.
Enzymes enable chemical digestion of nutrients:
o Pepsin – along with Hydrochloric Acid - Stomach – Proteins into amino acids
o Amylase – Saliva and Pancreas – Starches into disaccharides
o Lipases – Pancreas – Fats into fatty acids and glycerol
o Bile – Liver and Gall Bladder – Fats into fat globules
6
Absorption of nutrients takes place in the small intestine primarily, aided by secretions from
the liver and pancreas. Villi and microvilli absorb nutrients in small intestine.
o No food passes through the liver and the pancreas.
Components of food that are not digested leave the body as wastes.
No digestion takes place in the large intestines, but excess water and mineral ions are
absorbed through its wall.
Excretion
By removing toxic chemicals, excretion enables the body to maintain its osmotic (water
concentration) and pH balance.
Excretory Organs:
o Skin – excretes water, salts and nitrogen wastes.
o Lungs – carbon dioxide
o Kidneys – filter wastes out of the blood such as urea
Nephron – the functional unit of the kidneys – each kidney has about one million nephrons.
The kidneys filter wastes out of the blood and balance levels of molecules.
Metabolic wastes are removed from the body through the formation and excretion of urine.
Kidneys are vital to maintaining homeostasis, so damage to kidneys may eventually become
life-threatening.
Immune System –
Protecting Against Disease
Skin and mucous membranes form strong barriers that prevent pathogens from entering the
body.
When pathogens break through the body’s physical barriers, the body quickly responds with
second-line defenses—fever, inflammation, and the activation of special proteins that kill or
inhibit pathogens.
When a pathogen infects a cell, the body produces immune cells that specialize in detecting
and destroying that specific pathogen.
Eliminating Invaders
A specialized white blood cell called a helper T cells activates the specific immune response.
These cells coordinate two responses; the destruction of cells that have been infected by a
pathogen, and the removal of pathogens at large in the body.
Cytotoxic T cells attack and kill cells that have been infected by pathogens.
The B cell response removes extracellular pathogens from the body and prevents further
infection.
After an immune response, memory cells continue to protect the body from previously
encountered pathogens.
Immune System Dysfunctions
An allergic reaction is an excessive immune response to a normally harmless antigen.
In an autoimmune disease, the body launches an immune response so that body cells are
attacked as if they were pathogens.
When the immune system does not function, the body is unable to fight and survive infections
by pathogens that do not cause problems for a robust immune system.
Structures of the Nervous System
The central nervous system responds to internal and external information.
o Central Nervous System – the brain and the spinal chord.
7
The Peripheral Nervous System contains sensory and motor neurons that carry information
between the central nervous system and the rest of the body.
o Peripheral Nervous System branches throughout the body.
A spinal reflex is an involuntary movement triggered by sensory input and produced by neural
circuitry limited to the spinal cord.
Neurons and Nerve Impulses
Electrical signals in the nervous system are caused by the movement of ions across the cell
membrane of neurons.
Neurons are nerve cells consisting of
o Dendrites – act as antennae to receive information
o Axons – long projection of nerve cell that conducts electric impulses
o Axon Terminals – the end of the axons – how neurons communicate with other cells
o Myelin Sheath – insulation layer of axons
o Nodes of Ranvier – gaps between myelin sheaths that conduct nerve impulses.
A neuron’s dendrites gather information from other cells, the cell body integrates this
information, and the axon sends the information to other cells.
All nerve impulses begin when the resting state of a neuron is changed by a signal from
another neuron or from the environment.
Neurons communicate with other cells at specialized junctions called synapses.
Chemicals are released at synapses.
Sensory Systems
Specialized neurons called sensory receptors detect sensory stimuli and convert them to
electrical signals. These signals then can be interpreted by the brain.
The major classes of sensory receptors are photoreceptors, mechanoreceptors,
chemoreceptors, pain receptors, and thermoreceptors.
Specialized regions of the cortex detect different sensory information.
Nervous System Dysfunction
Many psychoactive drugs produce physiological dependence and addiction when abused.
Addiction occurs when repeated use of a drug alters the normal functioning of neurons and
synapses.
Damage to the nervous system can occur as a result of disease, traumatic injury, or exposure
to chemicals.
Hormones
The endocrine system regulates metabolism; salt, water, and nutrient balance in the blood;
controls the body’s response to stress; and regulates growth, development, and reproduction.
Endocrine glands and endocrine tissues produce and release hormones.
Hormones can affect only cells that have receptor proteins that match the hormone.
Amino acid–based hormones bind to the surface of target cells and cause changes by a second
messenger system. Steroid hormones enter target cells and cause changes by direct gene
activation.
The body uses negative feedback, positive feedback, and antagonistic hormones to regulate
the levels of hormones and their products.
8
Major Endocrine Glands
The hypothalamus and the pituitary gland work together to control the functions of the
endocrine system.
The thyroid gland, parathyroid gland, pancreas, and pineal glands regulate metabolism.
The adrenal medulla regulates short-term responses to stress. The adrenal cortex regulates
long-term responses to stress.
Reproduction is regulated by gonadotropins, which are released by the pituitary gland, and by
sex hormones, which are released by the gonads.
The Male Reproductive System
The male reproductive system has two testes that produce sperm and testosterone.
The vas deferens carries sperm into the urethra. Sperm leave the body by passing through the
urethra.
As sperm cells move into the urethra, they mix with fluids secreted by three exocrine glands:
the seminal vesicles, the prostate gland, and the bulbourethral glands.
After the semen is deposited in the female reproductive system, sperm swim until they
encounter an egg cell or until they die.
The Female Reproductive System
The ovaries produce egg cells. Ovaries also secrete estrogen and progesterone.
During the reproductive years, the female body undergoes a hormonal cycle that causes
periodic changes. These changes prepare the body in the event that an egg is fertilized.
If pregnancy does not occur, levels of estrogen and progesterone fall. The decrease in these
two hormones causes the lining of the uterus to be shed during menstruation.
Human Development
When a sperm cell encounters an ovum, the sperm cell releases enzymes that break down the
outer layers of the ovum. The head of the sperm enters the ovum, and the nuclei of the ovum
and sperm fuse. This process, from encounter to fusion, is called fertilization.
All of the embryo’s organ systems, as well as the supportive membranes that feed and protect
the embryo, develop during the first trimester of pregnancy.
By the end of the third trimester, a fetus is able to live outside the mother’s body. A baby
leaves the mother’s body after labor.
Sexually Transmitted Infections
Abstinence is the only sure way to protect yourself from contracting an STI.
Common STIs include genital herpes, genital HPV, trichomoniasis, HIV/AIDS, hepatitis B,
chlamydia, and gonorrhea.