The Structure and Functions of Cells: A Comprehensive Overview

The Structure and Functions of Cells

All living things came from one or more cells that are the simplest and smallest units of life. All cells came from pre-existing cells and each have a different function. It is a form of the membrane that is a border that separates cells from the environment, also where exchange of substances between cell and environment occurs. Also have cytoplasm that is a space where chemical reactions needed to carry out the vital functions and contain information of each cell and also genetic material that has a control system that direct the vital functions and where cell do the vital functions.

Nutrition and Metabolism

In nutrition, cells take molecules from the environment and transform into energy. There are autotrophic (create organic matter from inorganic matter) and heterotrophic (use inorganic directly). This occurs because of metabolism. At the end, waste products are released to the exterior. Interaction led cell to communicate and adapt to the conditions of the exterior.

Reproduction and Cell Size

Reproduction: there are unicellular (produce new living being) and multicellular (it substitutes dead ones and increases number of cells when organism is growing). Cells are measured in microns, size varies but not in cells of the same type and shape change a lot from one type to another and is related to the function they perform.

Prokaryotic Cells

Prokaryotic cells do not have a nucleus, are quite small, they have a cell wall surrounding the membrane, and a single circular chromosome. Also isolated ribosomes in plasma membrane also have foldings that work as mitochondria. Archaea (most primitive prokaryotic cell it nowadays live in extreme conditions), Cyanobacteria (could do photosynthesis, its activity gives oxygen to atmosphere), bacteria (live in almost all environments, they can be heterotrophic and autotrophic and depending on their shape they could be (cocci, bacilli, spirillia, and Vibrio).

Eukaryotic Cells and Organelles

Eukaryotic cells contain structures called organelles, the genetic material is in the nucleus and have cytoskeleton to maintain cell shape, internal organization and help cell movement. Organelles are found in cytoplasm, there are different organelles with different functions. Ribosomes can be found in cytoplasm or r.e.r. they are responsible for protein synthesis. Lysosomes are small vesicles that contain substances that digest molecules captured by cells, the endoplasmic reticulum is a form of complex set of tubules and vesicles that transport substances there is rough which have ribosomes and smooth, vacuoles store substances and there are more in plant cells than in animal cells. Golgi apparatus is a group of vesicles and sacs it takes substances from endoplasmic reticulum, changes them and introduces vesicles for secretion. Chloroplast is egg-shaped have sacs named thylakoids that contain the pigment that gives the Green color. Photosynthesis occurs here in this process chloroplast synthesis molecules from organic to inorganic using energy from the sun. Mitochondria has folds called cristae inside is the matrix which is made up of genetic material ribosomes and enzymes. They are cylindrical and made up of double membrane.