ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

The Key Differences Between Plant and Animal Cells

Updated on September 30, 2014

Figure 1 Diagram of a Chloroplast

Click thumbnail to view full-size

Figure 2 Diagram of a Plant Cell

Figure 3 Diagram of a Animal Cell

The three main differences between plant and animal cells is that of plastids, the cell wall and a large central vacuole, which will now be explained in greater detail (Davidson, 2005).

The first difference is that plant cells have plastids such as chloroplasts when animal cells do not [Fig 1] (Vasil and Vasil, 1972). Plastids are semi-autonomous organelles that are generally interconvertable and can divide independently of the cell. Their functions include storage, photosynthesis and pigment formation. Their properties include: a double membrane, having many copies of circular chromosomes, having a complete protein synthesis machinery, being the only site in the plant cells where lipid is made, they have genes lost to the nuclear genome. Each cell of the plant can only contain one type, since there are six main types: eoplasts (which are the most simple and consist of only a double membrane and DNA fibrils), etioplasts (which are from dark-grown leaves and have a prolamellar body for lipid storage), chromoplasts (which accumulate pigments e.g. flowers and have granum and thylakoids), amyloplasts (which store starch e.g. potato tubers, elatioplasts which store lipids e.g. anthers) and, finally, chloroplasts (Davidson 2005).

Chloroplasts are the most common type of plasmid and are found in all green tissues. Their function is to do photosynthesis which is where energy is trapped in the pigment chlorophyll, which is found in the chloroplasts. It is also this chlorophyll which makes many plants appear green, since it usually reflects green and yellow wavelengths of light. This process of photosynthesis converts carbon dioxide and water into sugars, releasing oxygen as a bi-product (Ridge, 2002). Chloroplasts have an outer membrane which is permeable to small molecules and an inner membrane which allows phosphate and sucrose precursors to be transported. They have single sheets forming numerous small interconnected flattened stack or grana to increase the surface area for light absorption. However animal cells only have mitochondria (which animal cells also have) so they are limited to only respiration.

Plastids are believed to have been formed from cyanobacteria, in endosymbiosis theory, which were very successful because of their ability to do photosynthesis. This is when water is utilised as an electron donor and carbon dioxide is taken up and then converted, using energy from the sun, into oxygen (a bi-product) and sugars-the same way it is still done today by chloroplasts within plants Over time, a few prokaryotic cells became large enough to become predators of the smaller, by attacking, engulfing and ingesting them. However, as endosymbiosis theory suggests, some of these smaller prokaryotes survived, leaving them still functioning within the other organisms (Gault and Marler, 2009). Thus, they provided sugars to the larger organism and received nutrients and CO2 in return, which slowly evolved into the chloroplasts of today.

A second difference between plant and animal cells is that while animal cells have only a cell membrane, plant cells also have a cell wall [Fig 2, 3]. It is essentially strands of cellulose running horizontally, ‘glued’ to each other by branched polysaccharides e.g. pectin (Burgert 2006), combined with the cell membrane and microtubules to help brace the membrane from the inside. Cellulose is made by b1-4 linkage joining molecules of glucose end-to-end. It is the most abundant organic molecule in the biosphere and a major structural component of plants, to the extent where cotton and paper are almost pure cellulose. Microfibrils are these long thin molecules of cellulose combined, which then themselves wind together to produce macrofibrils. In addition, the cell wall consists of lignin which has a supportive function because it is a very rigid molecule. Also, there are suberin cutin waxes which are fatty substances that are found on the outside surfaces of plat to help with waterproofing, to prevent dehydration via evaporation. The functions of the cell wall are: to lead the cells stability, determine its shape, influences its development, counterbalances the osmotic pressure and protects the cell against pathogens. It is the major structural material which plants are made from. This means that plant cells are more rigid in structure when animal cells are able to form different shapes.

Although vacuoles can sometimes be present in animal cells, they are must smaller and far less significant than those in plant cells [Fig 5, 6]. Young plants, too have small vacuoles but this then grows to the large central vacuole of maturity (Staley et al 2007). Vacuoles are membrane-bound sacs with little or even no internal structure. This surrounding membrane is called the tonoplast and is very active. Many mature plant cells have a single large central vacuole that have several important functions: they store foods (for example the proteins in seeds), they store wastes, they store special metabolites (e.g. malic acid) and they maintain tugor in the cell by filling the vacuole with water.

There are also several smaller differences between animal and plant cells. Cilia, for instance, are generally present in animal cells but they are very rare in plant cells. Also, centrioles are present in most animal cells but are only present in lower life forms. Lysosomes are generally present in the cytoplasm of animal cells when they are usually not evident in plant cells. To communicate between cells, plant cells have linking pores however animal cells use an analogue system of gap-junctions. In addition, plant cells can be totipotent. They are also non-motile.

Bibliography

Books

Purves et al (2004), Life the Science of Biology, Seventh Edition

Oxford Dictionary of Biology (2008), Sixth Edition, Oxford University Press

J Mauseth (2008), Botany: an introduction to plant biology, 4th edition, Jones and Bartlett

Staley et al (2007), Microbial Life, 2nd edition, Sinauer Associates Inc

Ridge (2002), Plants, Oxford University Press

Indra et al (2010), Plant Cell and Tissue Culture, Springer

Jensen (1970), The Plant Cell, 2nd edition, Fundamentals of Botany Series, Wadsworth Publishing

Gault and Marler (2009), Handbook on Cyanobacteria: Biochemistry, Biotechnology and Applications, Nova Science

Reports

Vasil and Vasil (1972), Totipotency and Embryogenesis in Plant Cells and Tissue Cultures, In Vitro

Burgert (2006), Exploring the Micromechanical Design of Plant Cell Walls, American Journal of Botany

Articles

Plant Cell (2010), Science Reference, Science Daily

Taiz and Zeiger, Plant Tissue Systems: Dermal, Ground and Vascular, Topic 1.4, 5th edition

Cutler (2011), Collenchyma Cells: Provide Strength, Flexibility, Nature and Design

Journals

Esau (1953), Plant Anatomy, Issue 5

Paris et al (2000), Plant Cells Contain Two Functionally Different Vacuoler Compartments

Molz and Hornberger (1973), Water Transport Through Plant Tissues in the Presence of a Diffusable Solute

Websites

Davidson (2005), Plant Cell Structure, http://micro.magnet.fsu.edu/cells/plantcell.html, Florida State University

University of Waikato, Plant and Animal Evolution, http://sci.waikato.ac.nz/evolution/plantEvolution.shtml

Sengbusch (2003), Cell Types of the Epidermis, http://www.biologie.uni-hamburg.de/b-online/e05/05a.htm

Comments

    0 of 8192 characters used
    Post Comment

    No comments yet.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)