Plasma Membrane Structure

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Cameron Mills
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1 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

2 Plasma Membrane Structure

3 Cell Plasma Membrane Each cell is surrounded by a plasma membrane; it allows the selective transport, through specialized carrier proteins, of molecules and ions in and out of the cell.

4 Endocytosis Exocytosis

5 Cartilage in Light-microscopic Section Cells called chondroblasts synthesize and deposit, by exocytosis, materials that build up cartilage and other connective tissues.

6 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

7 Cycle of Energy and Nutrients

8 Plants Are Autotrophic Plants harness solar energy to drive photosynthesis, a process that converts carbons dioxide and water into glucose and oxygen.

9 Animals Are Heterotrophic Animals need to consume other organisms to stay alive. This bald eagle was fishing at the Llano river, Texas.

10 Metabolic Pathways Cells brake down nutrients and synthesize their own molecules in a complex metabolic network, in which one biochemical reaction becomes the starting material for the next one. Alberts et al. (4th ed. 2002)

11 ATP is the Energy-Rich Form of ADP Adenosine triphosphate (ATP) releases its energy as it is split (hydrolyzed) into adenosine diphosphate (ADP) and phosphate. It regains its energy as the linkage with phosphate is restored.

12 Cellular Respiration Generates ATP as Universal Energy Carrier

13 ATP Drives Cellular Work The protein shown here is myosin, which changes its conformation (and loses energy) during muscle contraction. The protein s original (energy-rich) state is restored when it receives a phosphate group from ATP, which turns into ADP and loses energy in the process.

14 Living Things Insert Themselves into the Flow of Energy From the Sun to Heat Loss.

15 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

16 The Defining Features of Stem Cell Lineages

17 Human skin in section. Epidermal cells (blue) originate from stem cells located in the germinative layer. As they mature, they are pushed via the spinous and granular layers into the horny layer, where they are sloughed off.

18 Red blood cells lose their nuclei as part of normal development. The differentiated cells have only a short life span.

19 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

20 The Messy Room Analogy is to show that maintaining order requires energy. Alberts et al. (4th ed. 2002)

21 Cells Maintain Exquisite Organization

22 Organs Are Cells Arranged in Specific Patterns, not in Pepper-and-Salt Mixtures. Alberts et al. (4th ed. 2002)

23 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

24 Guard Cells in Plants Campbell & Reese (2002) Guard cells respond to external signals. For instance, they close at night when gas exchange is not required for photosynthesis while water conservation is adaptive.

25 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

26 Temperature Control at Home Homeostasis costs energy: A home thermostat controls the temperature in a home by activating a furnace or air conditioning unit if the temperature departs from a set point or interval.

27 Temperature Control in a Mammal Mader S.S. (2007) The blood temperature is compared to the set point in the brain, which activates responses by blood vessels, sweat glands, shivering muscles, etc.

28 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

29 Protection by Shells Protists known as Foraminifera have protected themselves for >500 million years by shells cemented together from sand, other particles, and organic compounds

30 Protection by Poison Many plants protect themselves by synthesizing poisons. Herbivores learn to avoid such plants.

31 Protection by Mimicry In Batesian mimicry, a palatable or harmless species mimics an unpalatable or harmful model. Here a harmless hawk moth larva (left) puffs up its head and then looks like a snake (right).

32 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

33 Dividing Amoeba The parent cell s chromosomes have been duplicated, and identical sets of chromosome will reconstitute new cell nuclei. A cytoplasmic furrow pinches the cell into two genetically identical daughter cells.

34 Asexual Reproduction Freshwater polyps of the genus Hydra form buds that can pinch off as new individuals.

35 Sexual Reproduction Most multicellular organisms reproduce sexually by forming gametes containing only a single set of chromosomes (n).

36 The Germ Line Concept The germ line forms a continuous lineage of cells connecting successive individuals, in which they form eggs or sperm. The other cells collectively called soma - are temporary caretakers of the germ line.

37 What is Life? Living things distinguish self from non-self Organisms extract nutrients, energy from outside Living things renew their component parts Organisms maintain a high degree of order Living things respond to external signals Organisms maintain homeostasis Living things protect themselves Organisms reproduce and develop

38 Active Transport

39 Photoperiodism Campbell & Reese (2002)

40 Plasma Membrane Structure

41 Cellular Respiration

42 Plasma Membrane Structure

43 Three types of molecules (color) involved in connections between cells.

Biology Slide 1 of 20

Biology Slide 1 of 20 Biology 1 of 20 8-1 Energy and Life 2 of 20 8-1 Energy and Life Autotrophs and Heterotrophs Where do plants get the energy they need to produce food? Living things need energy to survive. This energy comes