Prokaryotes Key Points Biology Part 1 Entry Test Preparation. Kingdom prokaryote’s most important cramming key points for MDCAT Biology preparation. On Earth, prokaryotes are the most common and diverse group of organisms.
They are also very important to human life because, other than plant and animal species, they make up all of the earth’s living cells! Bacteria, Archaea, and Eukarya are the three parts of prokaryotic life that you should know about if you want to study them well.
Cells are the building blocks of all living things. They are tiny units that work together to make organisms. All cells, no matter how big or small, have DNA, which stores instructions to help them work right. But not all cells are alike.
Plant and animal cells are different in size and shape, but their jobs and contents are very similar. At the level of the cells, however, there is a big difference: Animal cells have nuclei (singular is nucleus), and plant cells don’t.
Bacteria are One Type of Prokaryote:
The first thing you need to know about Prokaryotes is that they are not what you might think they are. You may have heard that bacteria are always bad and that you should do anything you can to avoid them. The opposite couldn’t be more true! We usually think of bacteria as germs and things that make us sick, but most of the bacteria we come across every day actually help us.
In fact, there is evidence that we couldn’t live without some bacteria in our guts. They help digestion and the immune system work better, help the body absorb nutrients, reduce inflammation, and even keep moods steady by making neurotransmitters like serotonin and dopamine.
What Do They Look Like?
Prokaryotic cells are smaller than eukaryotic cells, and they do not have a nucleus, organelles, or chloroplasts. The shape of a single prokaryotic cell depends on the species and what it does, but bacteria are usually round. As you’ll find out in the rest of Chapter 8, Some bacteria, such as spirochetes and vibrios, are in the shape of a spiral.
Some look like rods (like bacilli), some look like balls with wavy surfaces (like spirilla), and others may grow in clumps that don’t look like anything else (such as mycoplasma). There are a lot of differences between species, which can make it hard to tell them apart just by looking.
Functions – Both Inside and Outside Their Cells:
To understand prokaryotic cells, it helps to think of them as carrying out three basic tasks at the same time. The first is to get more energy by using what you already know (i.e., grow and survive). Second, they make more of themselves to have more babies. Lastly, they change to fit their environment, which doesn’t matter much whether it’s dry and hot or cold and wet.
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Prokaryotes Key Points(Cramming Notes)
Prokaryotes key points that can help you to cover the conceptual points of whole topic. The list is given below.
- Prokaryotes are organisms whose cells do not contain a distinct nucleus, bounded by a nuclear envelope,
- About f300 species’ of Prokaryotes have been identified.
- Prokaryotes include both the bacteria and the “Archaea, which appear to be only distantly related to bacteria.
- Archaea are single-celled microorganisms with structures similar to bacteria.
- They are evolutionarily distinct from bacteria and eukaryotes.
- Archaea are obligate anaerobes living in environments low in oxygen (eg., water, soil).
- Archaea live in both extreme conditions and moderate environments.
- Archaea inhabiting extreme environments are called extremophiles.
- Extremophiles are further divided into extreme halophiles and extreme thermophiles.
- Extreme halophiles live in a high salt environment such as Utah’s Great
Salt Lake and the Dead Sea.