Fundamentals of biology

1. Fundamentals of Biology

2. 4.1 The Ingredients of Life A. The Building Blocks 1 Organic compounds – molecules containing C, H, & O Make life possible High-energy molecules Energy used to synthesize Energy released in breakdown Four types of organic compounds

3. 2 Carbohydrates – sugars Glucose – metabolized for energy Starches – long chains of simple sugars used for energy storage Chitin – skeletal material Cellulose – cell structure

4. 3 Proteins Chains of amino acids Muscles are mostly made up of proteins Enzymes – catalyze reactions Structural proteins – skin, hair, skeleton Hormones

5. 4 Lipids Fats, oils, & waxes Energy storage – more than twice as much as sugar Water repellant Buoyancy Insulation Hormones

6. 5 Nucleic Acids Store and transmit the genetic information of all living things Long chains of subunits called nucleotides DNA – instructions for the construction and maintenance of an organism; the complete set is called the genome The nitrogen bases are sequenced into genes that code for a specific protein RNA – helps DNA

7. B. The Fuel of Life ATP – the molecule used to store energy; like a rechargeable battery You use ~ 125 lbs./day Organisms need to capture, store and use energy Most organisms use only two sets of reactions

8. 1 Photosynthesis: Making the Fuel Algae, plants, and some microorganisms Capture the sun’s energy and use it to make glucose The pigment chlorophyll captures the solar energy CO 2 + H 2 O → C 6 H 12 O 6 (glucose) + O 2 We rely on photosynthesis for food and oxygen Organisms that photosynthesize are called autotrophs Plants on land; bacteria and algae in the ocean

9. 2 Respiration: Burning the Fuel Both autotrophs and heterotrophs do it Releases the energy from org. compounds Reverse of photosynthesis Organic matter (glucose) + O 2 → H 2 O + CO 2 Similar to burning wood or oil Chemical energy captured in ATP Aerobic – uses oxygen, more efficient Anaerobic – does not use oxygen, less efficient

10. 3 Primary Production Most of the glucose is used for fuel or converted into other types of org. compounds The organic matter autotrophs make is called primary production Used by the organism for growth and reproduction Autotrophs are also called producers

11. 4 The Importance of Nutrients Vitamins, minerals and other substances are needed to convert glucose into other org . compounds Nitrogen for proteins & nucleic acids Phosphorus for nucleic acids Silica (SiO 2 ) to make shells Iron – necessary, but a limited resource in the ocean

12. 4.2 Living Machinery Organic compounds are organized into functional units that are alive

13. A. Cells and Organelles Cell – basic unit of life All organisms are made of cells Wrapped in a cell membrane Cell is filled with jelly-like cytoplasm Organelles have specific jobs in the cell

14. 1. Structurally Simple Cells: Prokaryotes Prokaryotes are primitive cells Ancient, simple, small No membrane-bound organelles Bacteria Prokaryotes have few structures: Cell wall – support Ribosomes – assemble proteins DNA – loose in the cytoplasm Flagella – locomotion

15. 2. Structurally Complex Cells: Eukaryotes Eukaryotic cells are organized and complex Larger than prokaryotes Have specialized organelles: Nucleus – contains chromosomes (DNA) Endoplasmic reticulum – make proteins and other org. molecules for the cell Golgi apparatus – package and transport molecules Mitochondria – respiration center to provide energy Flagella and cilia – for movement Only in plant & algal cells Chloroplasts – photosynthesis center Cell wall - support

16. B. Levels of Organization 1. A cell is self-contained and can carry out all the functions necessary for life Unicellular – all prokaryotes and some eukaryotes Multicellular – most eukaryotes Human body has 100,000,000,000,000 cells In multicellular organisms cells specialize to perform different tasks for the organism Cells that act together for a specific job are called tissues Muscle, nervous, bone, blood, epithelial Tissues are organized into organs to carry out specific functions Liver , kidney, heart, skin, brain Organs act together in an organ system Skeletal, muscular, excretory, endocrine, digestive

17. 2. Organization exists outside the individual organism Species – one type of organism Blue mussel Population – a group of one species A bunch of blue mussels Community – several different populations that live and interact in an area Blue mussels, crabs, barnacles, & chitons living on a rock Ecosystem – the communities living together with the physical environment Living on a rocky shore with seawater, air, temperature , sunlight , etc.

18. 4.3 Challenges of Life in the Sea Marine organisms must cope with different problems than on land They have evolved ways to adapt to their marine habitat Most important is maintaining homeostasis Keeping their internal condition normal regardless of the external condition

19. A. Salinity Marine organisms are immersed in a medium – sea water – that can greatly affect their cell function Enzymes and organic molecules are sensitive to ion concentration (salinity)

20. 1. Diffusion and Osmo sis Dissolved ions move around in water Random movement spreads them out in an even distribution Results in diffusion – movement from high low concentration When concentrations are different inside and outside a cell, substances will move in/out by diffusion Salt from seawater will diffuse into the cell Nutrients will diffuse out of the cell The cell membrane blocks block diffusion It’s selectively permeable – it allows only some substances to go in/out

21. Water is a small molecule and can fit through the cell membrane It also diffuses from high → low concentration If a cell has more solutes inside than outside, water will stream in and swell the cell If the seawater has more salt, water will leave and the cell will shrivel This diffusion of water is called osmosis Cells may need to move materials against diffusion (low high) e.g. expelling extra salt or taking in more sugar Active transport – proteins in the cell membrane pump materials using ATP 1/3 of the cell’s energy is spent on this

22. 2. Regulation of Salt and Water Balance Marine organisms have adapted ways to balance water and salt Osmoconformers –their internal concentrations change with the salinity of the seawater Live in a narrow range of salinity Osmoregulators – control internal concentrations to avoid osmotic problems Can tolerate changes in salinity better Can change their internal concentrations to match the seawater Salt water fishes lose water by osmosis Drink water or reduce urine amount to replace lost water Excrete excess salts in the urine or through the gills

23. Freshwater fishes gain water by osmosis Don’t drink water or produce lots of urine Salt absorbed by gills Some marine birds and reptiles have special glands to get rid of excess salt Most algae have rigid cell walls that resist the swelling caused by osmotic water gain

24. B. Temperature Metabolic reactions speed up/slow down when temperature goes up/down Metabolic rate doubles every 10oC At extreme temps most enzymes cease to function Marine organisms are adapted to live in a temp range Thus determining what regions of the oceans they live

25. Ectotherms – “cold blooded” lose their heat to the seawater Endotherms – “warm blooded” retain heat and keep their body temp higher than the water Mammals, birds, and some large fishes Poikilotherms – body temp changes with the temp of the seawater Incl. all ectotherms & endothermic fishes Homeotherms – keep internal temp the same, regardless of outside temp Produce more heat as need to keep their metabolic activity high Mammals & birds They need to eat more food Insulate their bodies with feathers, hair, and blubber

26. C. Surface-to-Volume Ratio Heat and materials exchange across the surface of an organism The surface-to-volume ratio (S/V ratio) determines how rapidly this happens As organisms get larger the volume grows faster than the surface area Small organisms rely on diffusion Large organisms respiratory and excretory systems

27. 4.4 Perpetuating Life A species must reproduce or vanish from the planet Produce a new offspring Pass on the genetic information

28. A. Modes of Reproduction Cells reproduce through cell division Cell fission in prokaryotes; mitosis in eukaryotes Results in identical daughter cells

29. 1. Asexual Reproduction No partner Offspring are genetically identical – clones Most single-celled organisms reproduce this way Some multicellular organisms do: Some sea anemones will split in half, making two smaller ones – fission Some sponges develop growths that break off to become separate individuals – budding or vegetative reproduction

30. 2. Sexual Reproduction Union of two separate gametes from two parents Ovaries – female gonads that produce eggs Testes – male gonads that produce sperm Meiosis divides the chromosomes in half; Fertilization combines them to form a full set again A fertilized egg is called a zygote. It has DNA from both parents This genetic recombination causes variation in the offspring Greatest advantage of sexual reproduction The zygote divides by mitosis and eventually forms an embryo May pass through a larval stage on the way to adulthood

31. B. Reproductive Strategies The goal of reproduction is to pass on the genes Varying reproductive strategies to get the same result Broadcast spawning – release millions of eggs and sperm into the water No parental care, most die Have few offspring and invest more time and energy into their survival Some use sexual and asexual reproduction Some species are hermaphroditic, both sexual organs

32. 4.5 The Diversity of Life in the Sea The vast diversity of organisms in the ocean came through millions of years of evolution The gradual alteration of a species’ genetic makeup

33. A. Natural Selection and Adaptation Individual organisms show variation in how they: Find food, avoid being eaten, reproduce, find mates, metabolize, etc. The best-adapted produce more offspring than the others This process is called natural selection As their genes get passed on the favorable traits become more common The population’s genetic makeup changes over time as it adapts to its environment Populations either adapt to the changes in the environment or become extinct

34. B. Classifying Living Things To discuss the huge variety of life forms we must first classify them 1. The Biological Species Concept What is a species? A type of organism? A population with common characteristics that can successfully breed with each other (fertile offspring) If two populations cannot interbreed they are reproductively isolated

35. 2. Biological Nomenclature Organisms are identified with a two-word name - Genus and species Blue whale – Balaenoptera musculus Fin whale – Balaenoptera physalus Minke whale – Balaenoptera acutorostrata Latin or Greek is used for naming Common names are confusing, scientific names are used worldwide to precisely identify a species

36. Levels of Classification Domain Kingdom Phylum Class Order Family Genus Species

37. 3. Phylogenetics : Reconstructing Evolution Organisms are grouped according to their relatedness Related organisms share an evolutionary history, or phylogeny They share a common ancestor Look at fossil record, anatomy, reproduction, embryological development, DNA, behavior, etc.

38. 4. The Tree of Life Classifications have changed over time Started with two kingdoms – Animalia and Plantae Then five kingdoms – added Fungi, Monera , & Protista Then three domain system