Unit 1: Levels of Organization of the Human Body

The Molecules of Life (Biomolecules):

WATERInorganic: (common to non-living and

living matter)

MINERALS

CARBOHYDRATES

LIPIDS (only in living matter

they all contain C)

PROTEINS

NUCLEIC ACIDS

Organic:

ANIMAL CELL

Eukaryotic Cell: Animal Cell

Cell Membrane

A phospholipid bilayer with

proteins.

Isolates the cell and controls the

substance exchange with the

medium.

Cytoplasm

Content of the cell:

Cytosol (liquid): water and soluble substances.

Cell Organelles

Nucleus

Controls the cell activity.

Double membrane, with pores.

Nucleoplasm.

Nucleolus (RNA+proteins): where

ribosomes are formed.

Chromatin (DNA+proteins)

transforms into chromosomes

when the cell is going to divide.

MitochondriaDouble membrane (outer and inner

The inner membrane forms cristae.

The inner space (matrix) contains

DNA and ribosomes!

They produce energy in a metabolic

process called cellular respiration.

Endoplasmic ReticulumSystem of membranes that

extend over the cytoplasm.

Two types:

ROUGH ER: with ribosomes

attached. Produces, stores and

trasnports proteins

SMOOTH ER: no ribosomes.

Produces, stores and

transports lipids.

Golgi Apparatus (or Complex)

Composed of membranous flat sacs piled

up forming stacks.

It modifies the substances that receives

from the ER, and secrets them outside the

cell.

LysosomesVesicles formed in the Golgi

Complex.

They contain digestive enzymes

that break down large

molecules or cell organelles.

If they broke, the cell would be

destroyed by them.

Vacuoles

Vesicles that store substances.

Plant cells usually have 1 or 2 big vacuoles.

Animal cells have many small vacuoles.

RibosomesPresent in all types of cells (prokaryotic and eukaryotic)

Composed of RNA and proteins. Produced in the nucleolus.

Not membranous.

May be floating free in the cytoplasm or attached to the RER

They synthesize (=produce) proteins.

Cytoskeleton

Only present in animal cells.

Composed of protein filaments of two types:

Microfilaments

Microtubules

Functions:

Helps the cell to divide (mitosis)

Contraction

Cell movement (form pseudopodia)

Transport inside the cytoplasm.

Form the centriols, cillia and flagella.

Centrosome

Only present in animal cells.

Composed of two centrioles,

one perpendicular to the other.

It organizes the cytoskeleton

and helps the cell to divide

(mitotic spindle)

Prokaryotic cellNo nucleus

Circular DNA floating in the cytoplasm

No membranous organelles

Ribosomes

Mesosomes

Cell wall covering

the Cell Memebrane

Capsule

Flagellum

PLANT CELL

Chapter 5 9

Generalized Cell Animal

Cell

PlantCell

Nucleus

Golgi

Mitochondria

EndoplasmicReticulum

Centrioles Chloroplasts

Eukaryotic Cell: Plant Cell

Chloroplasts

Only present in plant cells.

Like mitochondria, they have a double

membrane (outer and inner).

Like mitochondria, they have DNA and

ribosomes.

The inner membrane forms a system of

sacs piled up forming structures called

thylakoids. The stacks of thylakoids are

called grana.

The space inside the inner membrane is

called stroma.

They contain pigments like chlorophyll,

that make photosynthesis possible.

Cell Wall

Only present in plant cells.

It covers and protects the cell membrane.

It gives the cell a fixed shape.

Formed by a matrix of cellulose molecules.

HUMAN TISSUES

Simple Epithelial Tissues

Pseudostratified Epithelial Tissues

Stratified Epithelial Tissues

EPITHELIAL TISSUES

Types of Epithelia

Simple ColumnarSimple Cuboidal

Simple Squamous

Stratified Squamous Epithelium

Pseudostratified Columnar Epithelium

CONNECTIVE TISSUES

Cells (Fibroblasts) + Fibres + Extracellular matrix

Loose Connective Tissue

Cells (Adipocytes) + Extracellular Matrix

Adipose Tissue

Cells (Fibroblasts) + Fibres (collagen) + Extracellular matrix

Dense Connective Tissue

Cartilage Tissue

Cells: Chondrocytes

Extracellular Matrix

(elastic)

Bone Tissue

Cells (Osteocytes) + Extracellular Matrix (hard, calcified)

Blood

Cells Red Blood CellsWhite Blood CellsPlatelets

+ Liquid Extracellular Matrix (plasma)

MUSCLE TISSUE

STRIATED, INVOLUNTARY

STRIATED, VOLUNTARY

NO STIATIONS, INVOLUNTARY

NERVOUS TISSUE

Neurons:

Neurons with a Glial Cell (Astrocyte)