Animal Cells and Tissues

Homeostasis

[similar] + [condition] -maintain a stable internal environment despite changes in external environment

Homeostasis examples

body temp regulation, blood glucose regulation, osmoregulation

biological hierarchy

cell → tissue → organ → organ system → organism

cell specialization

certain cells are formed into specific tissues to perform specific tasks e.g. muscle cells → muscle tissues

primary tissues

epithelial, nervous, connective, muscle

epithelial tissues

Sheets of cells that cover surfaces and form barriers which must allow for secretion, absorption, and transportation of other molecules

Simple squamous epithelium

A

Stratified squamous epithelium

B

Simple cuboidal epithelium

C

stratified cuboidal epithelium

D

simple columnar epithelium

E

Stratified columnar epithelium

F

Pseudostratified

Name this special epithelial cell type

Transitional

Name the epithelial cell type

Connective tissue

Supports, binds, and protects other tissues and organs. Characterized by having relatively few actual cells.

Types of connective tissue

fibroplasts, adioplasts, extracellular substance (ground substance)

Extracellular substance

collagen, elastin, reticulin

loose and dense

2 characterizations of connective tissue

cartilage (chondrocytes) and bones (osteocytes)

specialized connective tissues

skeletal muscle tissue (striated)

majority of muscle tissue in animal body, voluntary contraction, multinucleated

cardiac muscle (striated)

only found in heart, involuntary contraction, branched and connected by intercalated discs, mononucleated

smooth muscle

found in most organs, involuntary, spindle shaped, mononucleated

nervous tissues

tissues responsible for communication, control, coordination

soma

cell body

dendrites

input region

axon

output region

myelin sheath

A fatty later that acts as electrical insulation

axon terminals

where a neuron forms a synapse

nerve signal

aka action potential, triggers a series of reactions that allow the muscle to contract

digestive system

mouth, esophagus, stomach, intestines, liver, pancreas

circulatory system

heart, blood vessels, blood

respiratory system

nose, trachea, lungs

nervous system

brain, spinal cord, nerves

reproductive system (male)

testes, vas deferens, prostate gland, penis

reproductive system (female)

ovaries, fallopian tubes, uterus, vagina

Water cell composition

70-90%

Protein cell composition

7-22%

Lipid cell composition

1-95%

Inorganic matter cell composition

1-2%

Carbs and others cell composition

1.5%

Water in cells

Largest constituent in cells, universal solvent, reaction medium, structural support, transport, thermal regulation

Universal solvent

Water’s ability to dissolve most substances and transport components around the body

Osmotic pressure

Pressure exuded by water on a cell when it moves to a place of high solute concentration from low solute concentration

Osmosis

The movement of water across a concentration gradient

Thermal regulation

Water’s high specific heat helps to maintain homeostasis

Intracellular fluid

Water inside of cells account for 40% of body weight

Extracellular fluid

Water outside of cells accounts for ~20% of body weight

Interstitial fluid

ECF surrounding cells accounting for 15% of body weight

Blood plasma

ECF in the blood counting for 5% of body weight

Conjugated proteins

Proteins that are attached to another molecule (prosthetic group)

Glycoprotein

A conjugated protein with a carbohydrate

Chromoprotein

A conjugated protein with with a colored substance able to be lit up

Structural and reactive

2 protein classifications

Structural protein

Provide support, strength, and cell shape. Examples include connective tissue and keratin

Reactive protein

Provide biochemical reactions and regulation. Examples include pepsin (enzymes), insulin (hormone), hemoglobin (transportation), and myosin + actin (contraction)

Lipids

Play roles in energy storage, cell signaling, membrane structure, and are insoluble in water

Fatty acids

main building block of lipids composed of carbon and hydrogen tails with a carboxyl group head

Triacylglycerol

Forms 90% of acylglycerols, consists of a glycerol head with 3 fatty acid tails. Must be further metabolized in order to be used in the body as glycerol and fatty acids.

Diacylglycerol

metabolic intermediate and signaling molecule with 2 fatty acid tails

Monoacylglycerol

Digestion and absorption intermediate with one fatty acid tail

Phospholipid

Similar structure to a triglyceride with the addition of a phosphate group in the head alongside more unsaturated fatty acid tails. Known for making up semi permeable membranes.

Steroids

Lipid not built from fatty acids, rather 3 six-membered rings and 1 five-membered ring. Examples include cholesterol, bile salts, and hormones like testosterone

Deoxyribose

DNA carbohydrate backbone

Ribose

Carbohydrate backbone in RNA

C, H, O, N

99% of elements in animal cells

P, Ca, Cl, K, Na, Mg

1% of elements in animal cells (with special emphasis for in class)

Cell membrane

Outer boundary of the cell that separates the cytoplasm from the external environment. Serves as a barrier, transport regulation, communication, signaling, and structural support

Fluid mosaic model

Model to describe cell membrane composed of a patchwork with phospholipids, membrane proteins, and cholesterol

Phospholipid bilayer

Thin barrier around all cells that comprises 50% of the total membrane. Key characteristics are amphipathic (hydrophobic and philic), selective permeability, and fluidity

Integral proteins

Proteins wedged into the the membrane among the phospholipids

Transmembrane proteins

A special type of integral protein that goes fully into the membrane to be exposed to the cytosol and out into the external environment.

Peripheral proteins

Proteins bound only to the surface of the membrane

Transporter protein

Integral protein (transmembrane) that moves molecules across the membrane

Recognition protein

Peripheral/glycoprotein that acts as identification of cell type or origin by other cells

Receptor protein

Integral protein that binds to hormones outside the cell and activates signaling inside the cell

Anchor or structural protein

Integral or peripheral protein that connects the cell membrane to the cytoskeleton or extracellular matrix for stability and shape

Cholesterol

A steroid that helps to regulate membrane fluidity by keeping phospholipids from separating under hot conditions or prevents them from bunching up under cold conditions.