BIOS 1030 OU Mohamed Tegany

Biology

The study of life

Characteristics of life

Require energy/materials; composed of cells; maintain homeostasis; respond to environment; grow/reproduce; populations evolve

Homeostasis

Maintaining stable internal conditions

Scientific method

Observation → hypothesis → prediction → test → revise

Hypothesis

Testable explanation for an observation

Theory

Well-supported explanation based on evidence

Control group

Group without experimental change

Independent variable

Manipulated factor in an experiment

Dependent variable

Measured outcome in an experiment

Atom

Smallest unit of an element

Molecule

Two or more atoms bonded together

Ionic bond

Electron transfer between atoms

Covalent bond

Electron sharing between atoms

Hydrogen bond

Weak attraction between molecules

Water properties

Solvent; temperature regulation; participates in reactions

pH

Measure of hydrogen ion concentration

Acid

Substance that donates hydrogen ions (H+)

Base

Substance that accepts hydrogen ions (H+)

Buffer

Substance that resists pH change

Carbohydrates

Molecules used for energy and structural support

Lipids

Molecules used for long-term energy storage and membranes

Proteins

Molecules made of amino acids; structure and enzymes

Enzyme

Protein catalyst that speeds reactions

Nucleic acids

DNA and RNA; store genetic information

ATP

Energy carrier molecule of cells

Prokaryote

Cell without nucleus or membrane-bound organelles

Eukaryote

Cell with nucleus and organelles

Nucleus

Control center of the cell; contains DNA

Ribosome

Site of protein synthesis

Endoplasmic reticulum

Membrane network producing proteins (rough) and lipids (smooth)

Golgi apparatus

Modifies, packages, and ships proteins/lipids

Mitochondria

Organelle producing ATP energy

Cytoskeleton

Internal support and movement structure

Plasma membrane

Phospholipid bilayer surrounding cell

Passive transport

Movement across membrane without energy

Diffusion

Movement from high to low concentration

Osmosis

Diffusion of water across membrane

Facilitated diffusion

Passive movement through membrane proteins

Active transport

Movement against gradient using ATP

Endocytosis

Bulk transport into the cell

Exocytosis

Bulk transport out of the cell

Metabolism

All chemical reactions in a cell

Anabolism

Building larger molecules

Catabolism

Breaking down molecules

Tissue

Group of similar cells with common function

Epithelial tissue

Covers and lines body surfaces

Connective tissue

Supports and connects body parts

Muscle tissue

Contracts to produce movement

Nervous tissue

Conducts electrical impulses

Neuron

Nerve cell that transmits signals

Glial cells

Support and protect neurons

Organ

Structure composed of multiple tissues

Organ system

Group of organs with shared function

Epidermis

Outer layer of skin

Dermis

Inner layer of skin

Skin functions

Protection; hydration; temperature regulation; vitamin D; sensation

Negative feedback

Mechanism that reverses a change

Positive feedback

Mechanism that amplifies a change

Bone

Living connective tissue forming skeleton

Compact bone

Dense outer bone layer

Spongy bone

Porous inner bone layer

Osteoblast

Bone-forming cell

Osteoclast

Bone-resorbing cell

Osteocyte

Mature bone cell maintaining tissue

Cartilage

Flexible supportive connective tissue

Ligament

Connects bone to bone

Tendon

Connects muscle to bone

Axial skeleton

Skull, vertebral column, ribs, sternum

Appendicular skeleton

Limbs and girdles

Joint

Connection between bones

Synovial joint

Freely movable joint

Arthritis

Inflammation of joints

Osteoporosis

Loss of bone density

Blood

Connective tissue for transport, regulation, defense

Plasma

Liquid portion of blood

Red blood cell (RBC)

Cell that transports oxygen

Hemoglobin

Oxygen-binding protein in RBCs

White blood cell (WBC)

Immune defense cell

Platelet

Cell fragment involved in clotting

Hematocrit

Percentage of blood volume that is RBCs

Hemostasis

Process that stops bleeding

Fibrin

Protein mesh forming blood clot

Blood type

Antigens present on RBC surface

ABO system

Blood types based on A and B antigens

Rh factor

Positive or negative blood antigen

Anemia

Reduced oxygen-carrying capacity of blood

Leukemia

Cancer of white blood cells

Thrombocytopenia

Low platelet count

Artery

Vessel carrying blood away from heart

Vein

Vessel carrying blood toward heart

Capillary

Tiny vessel for exchange with tissues

Heart

Muscular organ that pumps blood

Atrium

Upper chamber of heart

Ventricle

Lower chamber of heart

Atrioventricular (AV) valves

Valves between atria and ventricles

Semilunar valves

Valves at exits of ventricles

Pulmonary circuit

Blood flow between heart and lungs

Systemic circuit

Blood flow between heart and body

Cardiac cycle

Sequence of heart contraction and relaxation

SA node

Natural pacemaker of heart