Cell Biology

Hyndland Secondary School

National 5 Unit 1 - Cell Biology

Hyndland Secondary School

Biology Department

National 5 - Unit 1 Cell Biology

Summary Notes

2Unit Structure

4Cell structure

4Animal Cells

5Plant Cells

6Fungi

8Bacteria

10Uses of Single Celled Organisms

12Transport across cell membranes

12Cell Membrane

13Diffusion

14Osmosis

18Active transport

19Producing new cells

19Cell division

19Chromosome structure

20Mitosis

21Cancer

21Tissue Regeneration

22DNA, production of proteins and genetic engineering

23Protein Production

25Proteins.

26Enzymes

33Genetic Engineering

36Chemical energy in cells

36Photosynthesis

42Carbon Fixation

Unit Structure

Outline

The general aim of this Unit is to develop skills of scientific inquiry, investigation and analytical thinking, along with knowledge and understanding of cell biology. You will apply these skills when considering the applications of cell biology on our lives, as well as the implications on society/the environment.

The Unit covers the key areas of: cell structure; transport across cell membranes; producing new cells; DNA and the production of proteins; proteins and enzymes; genetic engineering; photosynthesis and respiration. You will research issues, apply scientific skills and communicate information related to your findings, which will develop skills of scientific literacy.

As a result you will be able to:

1 Apply skills of scientific inquiry and draw on knowledge and understanding of the key areas of this Unit to carry out an experiment/practical investigation

2 Draw on knowledge and understanding of the key areas of this Unit and apply scientific skills.

Homework

The homework is spilt into two types, written and online. The written homework is designed to help you learn problem solving skills and deals with graph drawing, calculations, data handling and experimental design and conclusion. Online homework contains some problem solving questions, but is more focussed on consolidating your knowledge of the course. Both types of homework are designed to help your preparation for the exam that forms a part of the Unit and also the external national 5 exam.

Tests

The unit includes 3 interim tests and a National 5 assessment at the end of the Unit.

QR codes

At points throughout this booklet you will encounter funny looking squares (like the one opposite). These are called QR codes and are like the bar codes on tins of beans. A mobile phone with a camera can be used to scan them and they then take you to a web page. In your summary notes, they typically take you to a Youtube video to help you better understand a particular part of Biology, or remind you of an experiment you have carried out in class, or even a 10 mark multi-choice quiz to help test your learning (the questions are selected at random, so you can use them again and again. If you start a quiz, you need to finish it and review your score, otherwise it can be difficult to start a new quiz).

To make use of them you need a little app, a phone, tablet or the like with a camera and access to the internet. The system has been tested using an Android phone with the app Quick Barcode scanner which is free to download; Blackberry offers the free, QR Code Scanner Pro-Free, which hasnt been tested; the Appstore also offers free QR code scanners, QR reader or Bakodo again not tested.

Please ask your parents permission to use this feature and as always ensure your security when downloading any app from the internet. In particular ensure you have disabled in app purchases before downloading any of the apps.

The links have been carefully selected by your teachers, however if you find any link that you think explains it better, please let us know and we will modify future editions for next session. Even better if you create your own version, give us the link and we can add it in. Enjoy your learning.

Cell structure

cell ultrastructure and functions to include cell walls, mitochondria, chloroplasts, cell membrane, vacuole, nucleus, ribosomes and plasmids in typical plant, animal, fungi and bacteria cells

Word Bank

aerobic respiration, cell sap, cellulose, controls, chemical reactions, function, information, photosynthesis, ribosomes, support, unicellular

Every living thing is made of at least one cell. The cell is the basic unit of life. Multicelluar organisms are made up of many cells that work together. ____________ organisms, such as Amoeba, are made of only one cell.

Animal Cells

All animal cells have:

A nucleus that contains ____________ and _________ the activities of the cell. The information is contained in chromosomes which are made of DNA. The DNA carries the genetic code for all the proteins a cell requires.

Cytoplasm, where most of the _______ __________ take place. The reactions are controlled by enzymes

Acell membrane that controls what enters and leaves the cell.

Mitochondria in the cytoplasm where ___________ _______________ takes place to release energy.

The ________________ are where proteins are made. Growing cells and cells producing digestive enzymes would have many of these in the cytoplasm.

Plant Cells

In addition to a nucleus, cytoplasm, cell membrane, ribosomes and mitochondria, plant cells also always have:

A cell wall made of ______________, which strengthens the cell and provides ___________.

They often have:

Chloroplasts* which contain the green pigment chlorophyll. This absorbs light energy for _____________.

A permanent vacuole filled with _____ _____ (a dilute solution of minerals, sugars and amino acids), which also provides support.

* Chloroplasts are only found in green parts of plants e.g. root cells dont have chloroplasts, being underground, they cant capture light and so cant photosynthesise. They therefore dont need chloroplasts.

Fungi

Word Bank

anaerobic, carbohydrate, carbon dioxide, cell wall, contamination, cytoplasm, decomposition, energy, fermentation, malting, maltose, optimum, photosynthesise, plant, respiration, starch, sterilising

The cells of fungi are similar to _________ cells. They have a nucleus, ______________, ribosomes and mitochondria. Whilst fungi do have a________ ________, it is made of chitin, a different type of ___________from cellulose. They are however not green they dont ________________and so dont contain chloroplasts. Fungi need to get nutrients and energy from other organisms. Fungi are involved in __________________- recycling nutrients from dead organisms back into the ecosystem. Humans have made great use of fungi, e.g. yeast are fungi and are used to make wine, beer and bread. Industrial Uses of Fungi

Yeast can use sugar as food to produce energy. It is used in BREWING and BAKING. In baking __________ ____________ produced by the yeast causes bread to rise. This is produced as a result of yeast respiring anaerobically.

In brewing (the manufacture of beer) and wine making the alcohol (ethanol) is produced by yeast performing _____________ RESPIRATION:

GLUCOSE ETHANOL + CARBON DIOXIDE + ENERGY*.

* As brewing occurs, the _________ released by yeast is detected as an increase in temperature the brew heats up! The carbon dioxide is released as a gas.

Anaerobic respiration by micro-organisms, such as yeast is called _______________.

In commercial breweries, the yeast are given the best possible conditions for growth by maintaining the following at _____________ levels:

Temperature

Oxygen supply

pH

glucose supply

They also ensure the brew is kept free from unwanted microbes, which would spoil the brew, by _____________ all the equipment using high temperatures and/or chemicals. ______________ would be expensive as the brew would need to be thrown away.

Beer is made from barley which is a seed. However, seeds, including barley only contain _________, which yeast cannot use as a food source. Consequently, the brewer has first to germinate the barley. This is called ___________ and as the seeds germinate, they produce an enzyme (amylase) which breaks the starch down into___________. The yeast then use anaerobic ___________ to change the maltose into alcohol.

Phospholipid

bilayer

Channel protein

protein

Starch

maltose

alcohol

Bacteria

Word Bank

chemical reactions, cytoplasm, DNA, mitochondria, plasmid, proteins

Bacteria have a much simpler structure than either plant or animal cells. They do not have ______________ , but do have _____________. The bacterial cell carries out all its____________ _____________, including aerobic respiration (which occurs in the mitochondria of the other cells types above) in the cytoplasm. In the cytoplasm, bacteria also have ribosomes, upon which bacterial ____________ are made.

Bacteria are the simplest of all cells. They dont have a nucleus, but keep their genetic information in a structure called a nucleoid, which is a large ring of________. In addition, they also have extra genetic information in a small ring of DNA called a ___________. These plasmids can be swapped between bacteria and usually help the bacteria survive e.g. by giving antibiotic resistance. Scientists have learnt to use plasmids to insert new genes, even human genes into bacteria (see .

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