iiiChapter 1 Elementary biochemistry

BiologyFor CAPE® Examinations

Claire Durant

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ISBN 978-0-230-03781-6

Text © Claire Durant 2013

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First published 2013

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On the cover: Pseudosphinx tetrio caterpillars are large (10–15 cm) with

velvety black, yellow and orange colouration that warns predators they

are poisonous. These caterpillars feed on frangipani and other plants

with milky sap. Caterpillars form a pupa from which a grey–brown

adult moth emerges. Pseudosphinx tetrio is common in the Greater

Antilles and is also found in the Lesser Antilles and the tropics.

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Commissioned photographs pages 3, 12C, 14CL, 14CR, 20, 21, 34BL,

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The author(s) and publishers are grateful for permission to reprint

the following copyright material: Figure 8.4 (page 113), map showing

distribution of P. falciparum malaria in Africa from S I Hay, et al (2009)

in PLoS Medicine 6(3):e1000048; Figure 22.4 (page 293) bar chart of

leading causes of death in the Caribbean from Data for Action Unite to stop the chronic non-communicable disease (CNDC) epidemic in the Caribbean. CARICOM Heads of Government Regional Summit

on CNCD on September 15, 2007; Table 22.1 (page 294) showing

preventive recommendations from Policy and Action for Cancer Prevention. Food, Nutrition, and Physical Activity: a Global Perspective. Washington DC: AICR, 2009; Figure 22.5 (page 297), graphs

summarizing HIV/AIDS in the Caribbean 1990–2011 from UNAIDS

Global Reports up to and including 2012; Table 22.2 (page 297)

showing prevalence of HIV in young males and females in 2001

and 2010; data from UNAIDS World AIDS DAY Report 2011; Figure

22.6 (page 298) bar chart of HIV prevalence among some high-risk

groups in selected Caribbean countries from UNAIDS World AIDS Day Results 2012; Figure 22.7 (page 298) graphs for AIDS surveillance in

Barbados from [PAHO].

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we will be pleased to rectify any errors or omissions at the earliest

opportunity.

Dr Claire Durant wishes to thank her parents Mr and Mrs James

Taylor for their love and support through this process as well as her

sisters Juliet, Peggy, Ruth and her friend Mr Louis Barrett. Dr Durant

acknowledges the assistance of Mr Simeon Archer.

ISBN 978-0-230-46576-3 AER

v

Contents

Investigations 47

Summary 48

Review questions 49

Answers to ITQs 49

Chapter 3 Enzymes and metabolic reactions in cells 50

Learning objectives 50

Factors affecting chemical reactions 50

Catalysts 51

Enzymes are the catalysis of metabolic

reactions 51

Mode of action of enzymes 51

Induced-fit hypothesis 51

Enzyme specificity 52

Factors affecting enzyme activity 52

Enzyme regulation 54

Enzyme inhibitors 54

Practical applications of enzymes 56

Investigations 57

Summary 57

Review questions 58

Answers to ITQs 58

Module 2 Genetics, variation and natural selection

Chapter 4 Structure and roles of nucleic acids 59

Learning objectives 59

Chemical structure and function of nucleotides 59

Structure and function of deoxyribonucleic acid 60

Expression of genetic information and

the genetic code 62

DNA replication 63

DNA proof-reading and repair 65

Structure and function of ribonucleic acid 66

Protein synthesis 67

The link between DNA, chromatin and

chromosomes 69

Applications of the principles of

DNA replication 70

Genetic control of phenotype 71

Investigations 72

Summary 72

Preface

Unit 1

Biomolecules, reproduction and

development

Module 1 Cell and molecular biology

Chapter 1 Elementary biochemistry 2

Learning objectives 2

Water 2

Acids, bases, the pH scale and buffers 6

Chemical structure and function of

carbohydrates 9

Importance of glucose, sucrose, starch,

glycogen and cellulose 11

Carbohydrates as organic building blocks 14

Chemical structure and function of proteins 15

Importance of haemoglobin and collagen 18

Chemical structure and functions of lipids 20

Chemical structure and function of

phospholipids 22

Testing for reducing sugar, non-reducing

sugar, starch, lipid and protein 22

Investigations 24

Summary 25

Review questions 25

Answers to ITQs 26

Chapter 2 Cell structure and function 27

Learning objectives 27

Comparison of the light microscope and the

electron microscope 27

Prokaryotes and eukaryotes 28

Features of the typical prokaryotic cell 28

Features of the typical eukaryotic cell 29

Structure and function of organelles 30

Endosymbiont theory 37

The fluid mosaic model of membrane structure 37

Movement of substances across biological

membranes 38

Tissues and organs 45

Cell communication 46

vi Contents

Review questions 73

Answers to ITQs 73

Chapter 5 Mitosis and meiosis 74

Learning objectives 74

The importance of mitosis 74

The maintenance of genetic stability 74

The stages of mitosis 74

The importance of the haploid and

diploid numbers 76

The stages of meiosis 77

Genetic variability and meiosis 79

Abnormalities in cell division 79

Down syndrome 79

Cancer as a genetic disorder 80

Investigations 80

Summary 81

Review questions 82

Answers to ITQs 82

Chapter 6 Patterns of inheritance 83

Learning objectives 83

The basis of Mendelian genetics 83

Monohybrid crosses 83

Law of segregation 84

Law of independent assortment 85

Dihybrid crosses 86

Analysing, interpreting and understanding

genetic experiments 87

Basic rules of probability 87

The chi-squared test 87

Incomplete dominance, codominance, epistasis,

hybrid vigour and sex-linked inheritance 89

Mendelian inheritance in humans 92

Investigations 93

Summary 94

Review questions 95

Answers to ITQs 95

Chapter 7 Genetic engineering 96

Learning objectives 96

Principles of biotechnology 96

Isolating and cloning genes 96

Applications and techniques of genetic

engineering in plants 98

Recombinant DNA applications in medicine 99

Human gene therapy 99

Human Genome Project 101

Transgenic plants 101

Transgenic animals 102

Transgenic microorganisms 104

Ecological concerns about genetically modified

organisms 104

Implications of using GMOs 105

Investigations 105

Summary 106

Review questions 106

Answers to ITQs 106

Chapter 8 Variation and natural selection 107

Learning objectives 107

Sexual reproduction as a mechanism to introduce

genetic variation 107

Phenotypic effects of mutations: sickle cell

anaemia, phenylketonuria, cystic fibrosis 107

Natural selection and evolution 109

Artificial selection and agriculture 110

Selection in natural populations 112

Types and causes of gene mutation 113

Environmental factors as forces of natural

selection 115

Mechanisms of natural selection 116

The biological species concept 117

The process of speciation 117

Mechanisms of reproductive isolation

of species 119

Investigations 120

Summary 121

Review questions 122

Answers to ITQs 122

Module 3 Reproductive biology

Chapter 9 Asexual reproduction and vegetative

propagation 123

Learning objectives 123

Types of asexual reproduction 123

Principles and importance of vegetative

propagation 127

Techniques and applications of tissue culture 128

Genetic consequences of asexual reproduction 129

viiContents

Investigations 129

Summary 130

Review questions 130

Answers to ITQs 130

Chapter 10 Sexual reproduction in the flowering plant 131

Learning objectives 131

Structure and function of flowers 131

Pollination and fertilisation 135

Mechanisms of self-fertilisation and

cross-fertilisation 136

Fruit and seed development 137

Fruit and seed dispersal 138

Genetic consequences of

sexual reproduction 139

Investigations 139

Summary 140

Review questions 140

Answers to ITQs 140

Chapter 11 Sexual reproduction in humans 141

Learning objectives 141

Sexual reproduction 141

The male reproductive system 141

The female reproductive system 145

The ovarian cycle 146

The uterine cycle 149

Fertilisation and implantation 149

Structure and function of the placenta 150

Pregnancy 151

Methods of birth control 154

Sexually transmitted diseases 154

Artificial insemination 156

Investigations 156

Summary 157

Review questions 157

Answers to ITQs 158

Unit 2

Bioenergetics, biosystems and

applications

Module 1 Bioenergetics

Chapter 12 Photosynthesis 160

Learning objectives 160

Anatomy and function of leaves 160

Structure and function of chloroplasts 162

The light-dependent stage of photosynthesis 162

Pigments of photosynthesis and their action

spectra 163

ATP synthesis 163

The Calvin cycle is light independent 166

Factors affecting photosynthesis 167

Investigations 168

Summary 169

Review questions 169

Answers to ITQs 170

Chapter 13 Cellular respiration 171

Learning objectives 171

Overview of aerobic respiration 171

Steps of glycolysis and the formation of

acetyl-CoA 172

Structure and function of mitochondria 174

The Krebs cycle 175

The electron transport chain 176

ATP synthesis 178

Energy yield from aerobic respiration 178

Anaerobic respiration: lactate fermentation and

alcohol fermentation 179

Investigations 181

Summary 181

Review questions 182

Answers to ITQs 182

Chapter 14 Energy flow and nutrient cycling 183

Learning objectives 183

Ecosystems, habitats and ecological niches 183

Energy flows in ecosystems 183

Energy losses at different trophic levels 184

Biomass 185

Biological pyramids 186

viii Contents

Composting 187

The nitrogen cycle 188

Ecosystems as self-sustaining units 190

Investigations 191

Summary 191

Review questions 192

Answers to ITQs 192

Chapter 15 Ecological systems, biodiversity and

conservation 193

Learning objectives 193

The dynamics of ecosystems 193

Biodiversity 193

The importance of maintaining biodiversity 194

Factors contributing to loss of biodiversity 198

In situ and ex situ conservation 200

Conservation in the Caribbean 203

Investigations 205

Summary 205

Review questions 206

Answers to ITQs 206

Module 2 Biosystems maintenance

Chapter 16 Uptake and transport of water, minerals

and products of photosynthesis 207

Learning objectives 207

Overview of transport in plants 207

Overview of plant nutrition 207

Structure and function of roots 207

Structure and function of xylem 211

Water movement in plants: transpiration

and the cohesion–tension theory 212

Structure and function of phloem 214

Transport of sugars in phloem: pressure flow

theory 216

Investigations 217

Summary 218

Review questions 218

Answers to ITQs 219

Chapter 17 Circulatory system of mammals 220

Learning objectives 220

Overview of mammalian circulation 220

Anatomy of the heart 220

The cardiac cycle 222

Composition and function of blood 223

Structure and function of blood vessels 225

Regulation of blood pressure 226

Capillary exchange 228

Cardiovascular disease 229

Overview of the respiratory tract 231

Principles of gas exchange 231

Transport of carbon dioxide and oxygen 231

Investigations 234

Summary 234

Review questions 235

Answers to ITQs 236

Chapter 18 Homeostasis and hormonal action 237

Learning objectives 237

Homeostasis 237

Principles of hormonal action 237

The human endocrine system 238

Functions of insulin and glucagon 241

Plant hormones: ethylene 242

Commercial use of plant hormones 243

Investigations 244

Summary 245

Review questions 245

Answers to ITQs 246

Chapter 19 Nervous coordination 247

Learning objectives 247

Differences between endocrine and nervous

communication 247

Overview of nervous communication 247

Organisation of the nervous system 248

Structure and function of neurones 248

The resting potential 251

Propagation of an action potential 253

Synapses and neurotransmitters 257

Postsynaptic potentials: temporal summation and

spatial summation 258

Effects of drugs and nerve agents on the nervous

system 259

Investigations 260

Summary 260

Review questions 261

Answers to ITQs 261

ixContents

Chapter 20 The kidney, excretion and osmoregulation 262

Learning objectives 262

Osmoregulation 262

Overview of the urinary system 263

Structure and function of the kidney 264

Urine production 266

Hormonal regulation of kidney function 269

Dialysis, kidney transplants and

kidney stones 270

Investigations 271

Summary 271

Review questions 272

Answers to ITQs 272

Module 3 Applications of biology

Chapter 21 Immunology 273

Learning objectives 273

Overview of the immune system 273

Innate immunity and acquired immunity 273

Overview of the lymphatic system 273

Barriers and non-specific defences

(cellular innate defences) 274

Specific defences: immunity 277

Immunoglobulins 278

The structure and function of the B cell

and T cell antigen-specific receptors 279

Clonal selection 281

Humoral and cell-mediated immune responses 282

Active immunity, passive immunity and

vaccination 284

Antibodies in medicine 284

Allergic reactions 285

ABO blood typing system and

the Rhesus factor 285

Investigations 286

Summary 287

Review questions 288

Answers to ITQs 288

Chapter 22 Health and disease 289

Learning objectives 289

Maintenance of health 289

Effects of diet and exercise on the body 289

Categorisation of diseases 292

Incidence rates and mortality rates 293

Chronic non-communicable diseases 293

HIV/AIDS 296

Dengue 299

Investigations 301

Summary 302

Review questions 302

Answers to ITQs 303

Chapter 23 Substance abuse 304

Learning objectives 304

Drug use 304

Effects of alcohol consumption on the body 305

Alcohol and violence 307

Alcohol and driving 307

Effects of cigarette smoking on the body 307

Investigations 309

Summary 310

Review questions 310

Answers to ITQs 310

Chapter 24 Practical biology and school-based

assessments 312

Techniques for biological drawing 312

Calculating magnification 314

How to use a microscope 316

Preparing a wet mount microscope slide 317

Microscopy measurement 317

Graphical representation of data 318

Planning and designing experiments 319

Data collection and analysis 319

Organising and presenting a report 319

How to plan and design an experiment 323

Study tips for biology tests and exams 324

Examples of experiments 324

Examples of 2 calculations 337

Examples of assessment criteria 338

Selected bibliography 340

Index 342

x

Preface

This series of textbooks for CAPE Sciences follows directly from

Macmillan’s CSEC Science series. The books in the series will be

especially valuable for students who have completed CSEC Science

examinations successfully, and wish to continue their studies at a

higher level, to gain employment in a scientific field or to extend their

education at degree level.

CAPE subject studies are each divided into two units, and students have

the option to study either or both of them. These books are designed

to be used with any of these three options. In each unit the material is

based on the knowledge and skills that the student will have gained in

CSEC studies.

The move to higher-level studies is not without its pitfalls. To minimise

these problems the books have several new and innovative features.

In the sciences a good diagram is worth a thousand words. Diagrams

in these books are carefully presented to convey the maximum

understanding with the minimum of extraneous detail. Their captions

are comprehensive, to help the reader to integrate the visual material as

fully and easily as possible with the text.

As in the familiar CSEC series, use is made of ‘In-text Questions’ (ITQ),

but at this level they provoke analytical thought rather than confirm

comprehension.

All science teachers are aware of fundamental misconceptions that

are commonly held. Throughout these books, notes are provided to

highlight and dispel these misapprehensions.

Dr Mike Taylor

Advisor