cell structure
TRANSCRIPT
CELL STRUCTURE
Andrijana Kološa 2nd year, 2013/2014School of Medicine
Starting point
living organisms cells
smaller pieces proteins and organelles
larger pieces tissues, organs and organ systems
About cellcell – basic structural and
functional unit tissues, organs
each cell different function
every cells reproduction, growth and development
One name, many types
TYPES OF CELLS:
1) prokaryotic cells (prokaryotes): eubacteria, archeabacteria
2) eukaryotic cells (eukaryotes – unicellular, multicellular ): - plant cells - animal cells (human cells)
cells unique to each type of organism
Cell specializationmulticellular organisms
different cell types that are adapted to particular functions
major cell types – skin cells, muscle cells, neurons, blood cells, fibroblasts, stem cells
most distinct cell types arise from a single totipotent cell(a zygote) that differentiates into hundreds of different cell types
Organellesparts of cell specialized for carrying out one or more
vital functions to the organs
several types1. typically solitary (nucleus, golgi apparatus)
2. numerous (mitochondria, chloroplasts, peroxisomes, lysosomes)
cytosol – gelatinous fluid that fills cell and surrounds the organelles
Cell membraneBiological membrane – envelops the cell
separation and protection from cell’s surroundings
selectively permeable – regulates what moves in and out
made mostly from a double layer of phospholipids
other functions: cell adhesion, ion conductivity and cell signalling
Cytoskeletonit acts to organize and maintain the cell’s shape
endocytosis; cytokinesis
moves parts of the cell in processes of growth and mobility
composed of microfilaments, intermediate filaments and microtubules
Endoplasmic reticulumtransport network for molecules
targeted for certain modifications
continuous with the outer membrane of the nuclear envelope endomembrane system
SMOOTH ER – lipid, phospholipid and steroid synthesis; sarcoplasmic reticulum
ROUGH ER – ribosomes; protein synthesis
Golgi apparatuspart of endomembrane
system
packages and modifies proteins inside the cell before secretion
involved in creation of lysosomes lysosomic vesicles
lysosomes – organells containing acid hydrolases intrcellular digestion
Mitochondrion "cellular power plants" generate
most of the cell's ATP
composed of specialized regions: outer membrane, intermembrane
space, inner membrane, cristae and matrix
its own independent genome
Nucleus "cell informaton center" houses
the ecell chromosomes
separated from cytoplasm by double membrane – nuclear envelope
DNA replication and RNA synthesis
nucleolus specialized region within nucleus where ribosome subunits are assembled.
Genetic materialDNA long-term information storage
RNA is used for information transport (mRNA)
enzymatic functions (rRNA)
adding amino acids during protein translation (tRNA)
genetic material contained in the cell nucleus and in the mitochondria
nuclear genome is divided into 46 linear DNA molecules called chromosomes
Replication
involves a single cell (mother cell) dividing into two daughter cells
prokaryotic – binary fission
eukaryotic – mitosis, meiosis
Protein synthesis
cells are capable synthesizing new proteins
two major steps: transcription and translation
Growth and metabolismprocessing nutrient molecules
two distinct divisions:
1) catabolism – cell breaks down complex molecules to produce energy and reducing power
2) anabolism – cell uses energy and reducing power to construct complex molecules
glycolysis; Krebs cycle
Movement or motilitycells move during processes – wound healing, the
immune response, cancer metastatis
three steps: 1. protrusion of the leading edge of the cell
2. adhesion of the leading edge and de-adhesion at the cell body and rear
3. cytoskeletal contraction to pull the cell foward
Resources
http://www.biology4kids.com/files/cell_main.html
http://en.wikipedia.org/wiki/Cell_(biology)
Cooper, Hausman: The Cell, A molecular approach, Sinauer Associates, 5th edition