Struktur Hewan

Structure of Animals Cells -basic unit of an animal’s structure -become specialized _______________________________ Tissues -made of cells that work together to perform a specific function __________________________________________ Organs -made of different types of tissues that work together to perform a specific function ____________________________________________________ Organ Systems -made of organs that work together to perform a specific function _____________________________________________________________ Organisms

Unicellular Organisms “uni-” = one Prokaryotes are unicellular organisms Some algae, some protists, and some eukaryotes (yeasts), are unicellular Can still do everything they need to stay alive Benefits over multicellular organisms: Need fewer resources Can live in harsher conditions

Two basic types of cells 1. prokaryote – cell without nucleus and other membrane bounded organelles. e.g eubacteria and archaebacteria 2. Eukaryote – cell with nucleus and membrane bounded organelles. e. g. protists, fungi, plants, animals.

Animal Cell

Multicellular Organisms “multi-” = more than one Plants, animals, some protists, and most fungi are multicellular Start as a single cell  many cells  cells differentiate (change) into different types of cells  cells group together Characteristic Larger size = have less predators and have more options of things to eat Longer life – organism will continue to live even if a single cell dies Specialization – each type of cell has a specific job, making the organism more efficient

Cell membrane- osmoregulator, semi-permeable, phospholipid bilayer, fluid mosaic model.

Cytoplasm Gel-like mixture Surrounded by cell membrane Contains hereditary material

Nucleus Directs cell activities Separated from cytoplasm by nuclear membrane Contains genetic material - DNA

Cytoplasm- fluid portion containing the nucleus and the rest of the organelles. Eukaryotes contain more genetic material than prokaryotes. Histones—proteins unique to eukaryotes—combine with the deoxyribonucleic acid (DNA) to pack the genetic material into compact chromosomes. The nuclear material is enclosed in a nuclear envelope formed of a double membrane. The fluid portion is nucleoplasm (karyoplasm or karyolymph. The nucleolus synthesize RNA. The pores are called nuclear pores

Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus http://library.thinkquest.org/12413/structures.html

Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html

Nucleolus Inside nucleus Contains RNA to build proteins http://library.thinkquest.org/12413/structures.html

RNA- Ribonucleic acid The mRNA molecule is ribbon-like, and is synthesized from DNA in a process called “transcription” in which the genetic code is transcribed from the DNA to the mRNA.

Types of RNA The mRNA joins temporarily to the anticodon of the tRNA. This protein building process takes place in the ribosomes of a cell, which consist largely of rRNA. The large and small subunits of a ribosome are marked in the third illustration above.© Transfer RNA is instrumental in the “translation” of the genetic code. Transfer RNAs are small structures in the form of “four-leaf clovers”. They each carry an amino acid that is added to the end of a growing protein chain. Ribosomal RNA

Ribosomes Each cell contains thousands Make proteins Found on ribosomes & floating throughout the cell http://library.thinkquest.org/12413/structures.html

Protein synthesis

Endoplasmic Reticulum Moves materials around in cell Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface http://library.thinkquest.org/12413/structures.html

Mitochondria Produces energy through chemical reactions – breaking down fats & carbohydrates Controls level of water and other materials in cell Recycles and decomposes proteins, fats, and carbohydrates http://library.thinkquest.org/12413/structures.html

Golgi Bodies Protein 'packaging plant' Move materials within the cell Move materials out of the cell http://library.thinkquest.org/12413/structures.html

Lysosome Digestive 'plant' for proteins, fats, and carbohydrates Transports undigested material to cell membrane for removal Cell breaks down if lysosome explodes http://library.thinkquest.org/12413/structures.html

Rough Endoplasmic Reticulum mitochondrion nucloeolus nucleus nuclear membrane Smooth Endoplasmic Reticulum

The smooth Endoplasmic Reticulum (smooth ER) isolates and transports lipids. The ribosomes which are attached to the rough ER make the proteins. The rough ER isolates and transports these proteins. Some ribosomes are not attached to the rough ER and exists free within the cytoplasm. Both types of ER are continuous with the nuclear membrane.

Mitochondrion- respiratory site of the cells (ATP)

Vesicles become pinched from the rough ER Vesicles become pinched from the rough ER. These join together to become the Golgi body (apparatus). The proteins become packaged and processed here. Eg. A carbohydrate may be added to produce a glycoprotein. Part of the Golgi body containing the packaged protein will be pinched off to form the secretory vesicles. These in turn merge with the plasma membrane and the packaged protein will be secreted from the cell.

Two main ways in which animal cells are bound together

Four functional classes of cell junctions in animal tissues

Cells  Tissues  Organs  Organ Systems

Cells Cells can be specialized (have a certain function) Function = job Function is related to the cell structure Structure = how parts of the cell are put together Shape Material it’s made from Structure of a brain cell is different from muscle cell

Tissues Tissue = group of cells that work together to do a specific job Ex: Heart muscle tissue is made of heart muscle cells Animals have 4 types of tissue: nerve, muscle, connective, protective

Organs Organ = structure that is made up of 2 or more tissues working together to get a specific job done Ex: Stomach – muscle tissue moves food, special tissues make chemicals to digest food, connective tissue holds stomach together, nervous tissue sends messages back and forth between the stomach and brain

Organ Systems Organ system = group of organs working together to perform a specific function Each organ system has a specific job Ex: Digestive system is made of several organs including the stomach and intestines