DSE Biology Chapter 1 - Cells and Molecules of Life PDF

DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1a. molecules of life 生命分子 i. carbohydrate 碳水化合物 ii. lipids 脂質 iii. proteins 蛋白質 iv. nuclei acids...

DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1a. molecules of life 生命分子 i. carbohydrate 碳水化合物 ii. lipids 脂質 iii. proteins 蛋白質 iv. nuclei acids 核酸 v. water 水 vi. minerals 礦物質 1b. light microscope 光顯微鏡 i. structure 結構 ii. steps of using 使用步驟 1c. cell 細胞 i. cell theory 細胞學說 ii. animal cell (Eukaryotic cells) 動物細胞 (真核細胞) iii. plant cell (Eukaryotic cells) 植物細胞 (真核細胞) iv. prokaryotic cells 原核細胞 v. cell membrane 細胞膜 vi. level of body organization 生物體的組織層次 1d. movement of substance across the membrane 物質穿越細胞膜的過程 i. diffusion 擴散 ii. osmosis 滲透 iii. active transport 主動轉運 iv. phagocytosis 吞噬 1e. cell cycle & cell division 細胞週期及細胞分裂 i. definition 定義 ii. mitosis 有絲分裂 iii. meiosis 減數分裂 iv. mitosis vs. meiosis 有絲分裂 vs. 減數分裂 1 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1f. metabolism 代謝作用 i. catabolism & anabolism 分解代謝和合成代謝 ii. enzymes 酶 iii. rate of reaction 反應速率 iv. inhibitor 抑制劑 v. 5 common enzyme experiment 5 個常見酶實驗 (1) Amylase 澱粉酶 (2) Protease 蛋白酶 (3) Ginger milk curd 薑汁撞奶 (4) Lipase 脂肪酶 (5) Catalase 過氧化氫酶 1g. photosynthesis 光合作用 i. experiment tools 實驗工具 ii. basic knowledge 基本知識 iii. factors input 輸入的因素 iv. rate 速率 v. photosynthesis rate vs. respiration rate 光合作用速率 vs.呼吸作用速率 vi. limiting factors 限制因素 vii. light reaction & dark reaction 光反應、暗反應 viii. chloroplast 葉綠體 ix photochemical reactions & carbon fixation (Calvin cycle) 光化學反應與碳固定 (卡爾文循環) x. photosynthetic products 光合作用產物 1h. respiration 呼吸作用 i. experiment tools 實驗工具 ii. aerobic respiration 需氧呼吸 iii. anaerobic respiration 缺氧呼吸 iv. glycolysis, Krebs cycle & oxidative phosphorylation 糖酵解、克雷伯氏循環 及 氧化磷酸化 2 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1ai. molecules of life – carbohydrate 生命分子 – 碳水化合物 (1) made up of C, H, O (H : O = 2 : 1) 由 C、H、O 組成 (H : O = 2 : 1) (2) Types 種類 a. Monosaccharide 單糖 (single ring of atoms 單環結構) e.g. glucose 葡萄糖 (6C), fructose 果糖 (6C), ribose 核糖 (5C) b. Disaccharides 雙糖 (2 monosaccharide join together by condensation 以縮合連結起兩個單糖) e.g. maltose 麥芽糖, lactose 乳糖, sucrose 蔗糖 c. Polysaccharides 多糖 (condensation polymers of monosaccharides 多個單糖分子的縮合聚合物) e.g. starch 澱粉, glycogen 糖原, cellulose 纖維素 have reducing power 有還原能力 insoluble in water 不溶於水 * for transporting food : it must be soluble in water 運輸的食物︰一定係溶於水 (3) Functions 功能 a. release energy 釋出能量 oxidize glucose through respiration 通過呼吸氧化葡萄糖 b. storage 貯藏 starch in plant, glycogen in animal 植物中的澱粉、動物中的糖原 c. support 支持 cellulose make cell wall to support plant / cellulose : for maintain the shape of plant cells 纖維素製造細胞壁支持植物 / 纖維素︰幫助植物細胞保持形狀 3 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1aii. molecules of life – lipids 生命分子 – 脂質 (1) made up of C, H, O (H : O > 2 : 1) 由 C、H、O 組成 (H : O > 2 : 1) (2) Types 種類 a. Triglyceride 甘油三脂 b. Steroid 類固醇 c. Phospholipid 磷脂 (3) Structure 結構 - insoluble in water, but soluble in organic solvents (e.g. ethanol) 不溶於水，但溶於有機溶劑 (例︰酒精) 1aiii. molecules of life – proteins 生命分子 – 蛋白質 (1) made up of many amino acids 由氨基酸組成 amino acids made up of C, H, O, N (sometimes includes S) 由 C、H、O、N (有時包 S) 組成氨基酸 (2) Functions 功能 a. as structural materials 作為結構性物質 main components of the cell membrane and cytoplasm 組成細胞膜和細胞質的主要成分 b. as an enzymes (biological catalysts) 作為酶 (生物催化劑) c. as energy source 作為能量來源 d. found in finger nails, chromosomes 於指甲、染色體發現 4 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1aiv. molecules of life – nuclei acids 生命分子 – 核酸 (1) made up of C, H, O, N and P 由 C、H、O、N 和 P 組成 (2) Types 種類 a. DNA (deoxyribonucleic acid) DNA (去氧核糖核酸) b. RNA (ribonucleic acid) RNA (核糖核酸) 1av. molecules of life – water 生命分子 – 水 (1) the most abundant substances in living cells 生命細胞內含量最多的物質 (2) Functions 功能 a. as a solvent for food and waste transport 用作運輸食物和廢物的溶劑 b. as cooling agent 用作冷卻劑 high specific heat capacity 高比熱容 c. as a raw material for photosynthesis 用作光合作用的原料 d. for hydrolyze of food molecules 將食物分子水解 1avi. molecules of life – minerals 生命分子 – 礦物質 (1) are inorganic ions 是無機離子 (2) Types 種類 a. Calcium 鈣 b. Phosphate 磷酸鹽 c. Iron 鐵 d. Magnesium 鎂 e. Nitrate 硝酸鹽 5 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1bi. light microscope – structure 光顯微鏡 – 結構 6 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1bii. light microscope – steps of using 光顯微鏡 – 使用步驟 Target ︰ onion epidermis 1. Peeling of epidermis Separate a thin tissue for observation 2. Staining with iodine solution Make cellular structure more distinguishable 3. Adding a drop of water Reduce the refraction of light 4. Lay a cover glass on the specimen Flatten the tissue (thin glass slide can increase the illumination) 5. Put the specimen on the stage 6. Turn on the lower power objective (the field of view is larger) (e.g. 10X) The light intensity is higher, so it is no need to use diaphragm / condenser to increase the illumination 7. Turn the coarse adjustment knob until the specimen is in focus It is easier to focus on the specimen at lower power objective 8. Search the field 9. Adjust the position of the slide until specimen is at the centre of the field of vision (the image is inverted) 10. Turn to the high power objective (e.g. 40X) 11. Adjust the diaphragm / condenser to increase the illumination of the slide Diaphragm regulates the amount of light passing through the condenser and brightens or dims the view so as to obtain a sharp image 12. Turn the fine adjustment knob until the specimen is in focus 13. Search the field (whole process keep both eyes open in order to avoid eyestrain) 7 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1bii. light microscope – steps of using 光顯微鏡 – 使用步驟 對象︰洋蔥表皮 1. 撕出洋蔥表皮 分出薄組織以供觀察 2. 用碘液染色 令細胞結構更明顯 3. 加入一滴水 減低光線的折射 4. 把蓋玻片蓋在樣本上 把組織壓平 (薄的玻片會增加光度) 5. 把樣本放在載物台 6. 轉動低倍接物鏡 (觀察範圍會更大) (例︰10X) 光度較高，所以無需要用光圈調節器 / 聚光器以增加照明 7. 轉動粗調節器直至樣本對焦 於低倍接物鏡時比較容易把標本對焦 8. 搜尋視野 9. 調校玻片位置，使樣本置於視野中央 (像是倒立 (上下左右倒轉)) 10. 轉動高倍接物鏡 (例︰40X) 11. 調校光圈調節器 / 聚光器以增加玻片的照明 光圈調節器控制透過聚光器的光量，使影像變亮或變暗以獲取清晰的影像 12. 轉動微調節器直至樣本對焦 13. 搜尋視野 (整個過程保持雙眼打開，以免眼睛疲勞) 8 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1ci. cell – cell theory 細胞 – 細胞學說 a. all living organisms are composed of one or more cells. 所有生物皆包含一個或多個細胞。 b. the cell is the basic unit of structure and organization in organisms. 細胞是生物的結構和組織中最基本的單位。 c. cells arise from pre-existing cells. 細胞是由以前存在的細胞中產生。 9 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1cii. cell – animal cell (Eukaryotic cells) 細胞 – 動物細胞 (真核細胞) Nucleus 細胞核 - large & centrally placed - 大及置於中央 - irregular-shaped - 不規則形狀 - controls cellular activities - 控制細胞運動 - stores genetic information - 貯存遺傳信息 - involved in protein synthesis - 涉及蛋白質的合成 Nuclear membrane 核被膜 - protect nucleus - 保護細胞核 Cell membrane 細胞膜 - selectively permeable - 選擇透性 Cytoplasm 細胞質 - hold many cell organelles - 包圍很多細胞器 - site for enzymatic reactions - 酶反應的所在地 - allow movement and transport of materials - 容許物質移動及運輸 Ribosome 核糖體 Rough endoplasmic reticulum 粗糙內質網 - synthesizes proteins  enzyme - 製造蛋白質  酶 - abundant in secretary cells - 大量存在於分泌細胞 e.g. insulin-producing cells in the pancreas 例︰產生胰島素的胰臟細胞 Smooth endoplasmic reticulum 光滑內質網 - manufacture of lipid - 合成脂肪 - detoxification - 解毒 Mitochondrion 線粒體 - generate energy through aerobic respiration - 通過有氧呼吸產生能量 for active transport 作主動運輸 - abundant in root hair cells & secretary cells - 大量存在於根毛細胞和分泌細胞 10 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1ciii. cell – plant cell (Eukaryotic cells) 細胞 – 植物細胞 (真核細胞) Nucleus 細胞核 - small and peripherally placed - 細小及置於外圍 - round shaped - 圓形形狀 - controls cellular activities - 控制細胞運動 - stores genetic information - 貯存遺傳信息 - involved in protein synthesis - 涉及蛋白質的合成 Cell wall 細胞壁 - freely permeable - 自由進出 Central vacuole 中央液泡 - filled with cell sap - 內含細胞液 - contain water & dissolved mineral salts - 含有水份及溶解的礦物鹽 Chloroplast 葉綠體 - not all plant cells have chloroplast - 不是所有植物細胞有葉綠體 - carry out photosynthesis - 執行光合作用 Size : chloroplast > mitochondrion > endoplasmic reticulum > ribosome 大小︰葉綠素 > 線粒體 > 內質網 > 核糖體 Light microscope 光學顯微鏡只見到 chloroplast 葉綠素 11 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1civ. cell – prokaryotic cells 細胞 – 原核細胞 No nucleus 沒有細胞核 No mitochondria 沒有線粒體 Have cell wall 有細胞壁 Have nucleic acid as genetic material 有核酸作遺傳物質 Have cell membrane 有細胞膜 Have cytoplasm 有細胞質 Special cells 特別細胞 1. Red-blood cell 1. 紅血細胞 - round shape (vs. angular shape) - 圓形 (vs. 多邊形) - mature : no nucleus - 成熟︰沒有細胞核 2. nerve cell 2. 神經細胞 - cannot move - 不能移動 - have a nucleus - 有細胞核 - have cell membrane - 有細胞膜 3. phagocyte 3. 吞噬細胞 - locomotion - 能夠行動 4. sperm 4. 精子 - contain a haploid set of chromosomes - 含有單套染色體 23 chromosomes 23 染色體 - locomotion - 能夠行動 5. ovum / egg cells 5. 卵子 - contain a haploid set of chromosomes - 含有單套染色體 23 chromosomes 23 染色體 - can undergo cell division - 進行細胞分裂 6. gametes cell 6. 配子細胞 - sperm & ovum - 精子 及 卵子 - vs. somatic cells - vs. 體細胞 contain a diploid set of chromosomes 含有雙套染色體 23 pairs of chromosomes 23 對染色體 46 chromosomes 46 條染色體 7. xylem vessel 7. 木質部 - no nucleus - 沒有細胞核 - no cell membrane - 沒有細胞壁 - no chloroplasts - 沒有葉綠素 12 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1cv. cell – cell membrane 細胞 – 細胞膜 W : membrane proteins 膜蛋白 1. Some serve as antigens for cell recognition / Recognition of pathogens 有些作為識別細胞的抗原。/ 識別病原體 2. Some serve as enzymes for cellular metabolism. 有些作為細胞代謝作用中的酶。 3. Some act as carriers (proteins) which transport some substances across the membrane. 有些充當載體(蛋白)，用以跨膜運送某些物質。 4. Transmission of nerve impulses across a synapse. 傳遞神經脈衝跨越突觸 5. Absorption of glucose in the small intestine 小腸吸收葡萄糖 X : transport proteins (ion channel) 運輸蛋白 (離子通道) - transport polar substances into the cell e.g. amino acid 將極性物質送到細胞內 例︰氨基酸 Y : phospholipid bilayer 磷脂雙分子層 - have a hydrophilic ionic head & a hydrophobic hydrocarbons tails 有一親水性離子頭及一疏水性烴尾 - only allows non-polar, lipid-soluble substance to pass through 只容許非極性、脂溶性物質通過 - non-polar (e.g. oxygen, fatty acid), lipid-soluble (e.g. vitamin A, D) molecules dissolve in and then diffuse across the phospholipid bilayer 非極性 (例︰氧氣、脂肪酸)、脂溶性分子 (例︰維生素 A、D) 溶於磷脂層 並擴散穿越細胞膜 - ions / polar molecules CANNOT pass through since ions are repelled by hydrophobic hydrocarbon tails 離子 / 極性分子 無法 通過因為離子會被疏水性烴尾排斥 Z : carbohydrate chain on a glycoprotein 糖蛋白的碳水化合物鏈 - signal reception 接收訊息 - antigenic function 作為抗原 Fluid-mosaic model 流動鑲嵌模型 Fluidity : lateral movement of phospholipid molecules Mosaic : protein molecules interspersed among phospholipid molecules in a mosaic pattern 流動︰磷脂分子可作橫向移動 鑲嵌︰蛋白質分子分散地 呈鑲嵌模式 嵌於磷脂分子之間 13 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1cvi. cell – level of body organization 細胞 –生物體的組織層次 a. cell 細胞 : red blood cell 紅血細胞 b. tissues 組織 : blood 血液 c. organs 器官 : heart 心臟 d. systems 系統 : circulatory system 循環系統 e. organisms 生物 : human 人類 14 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1di. movement of substance across the membrane – diffusion 物質穿越細胞膜的過程 – 擴散 Diffusion is a physical process that refers to the net movement of molecules from a region of high concentration to one of lower concentration. 擴散是一個物理過程指出分子由一個高濃度範圍到一個低濃度範圍的淨移動。 Factors affect the rate of diffusion 影響擴散速率的因素 1. temperature 1. 溫度 T increase, K.E. increase, speed increase, less time is required for diffusion 溫度上升、動能上升、速度上升、擴散的所需時間較短 2. concentration gradient 2. 濃度梯度 - concentration gradient increase, the greater the net movement of molecules to move from high concentration to low concentration - Rate of diffusion is directly proportional to the concentration gradient. - 濃度梯度上升，由高濃度到低濃度的分子淨移動上升。 - 擴散速率與濃度梯度成正比。 3. size of particles involved 3. 涉及的粒子大小 at the same temperature, smaller size molecules will have greater speeds, so the rate of diffusion increase. 於同一溫度下，較小型的分子會有較大的速度，所以擴散速率上升。 15 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1dii. movement of substance across the membrane – osmosis 物質穿越細胞膜的過程 – 滲透 Osmosis is the spontaneous net movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides. 滲透是溶劑分子經選擇透性膜的擴散現象，它由高水勢分子區域 (即低濃度溶 液) 淨移動至低水勢分子區域 (即高濃度溶液)，直至活細胞內外的濃度平衡為 止。 Water potential is potential energy of water per unit volume relative to pure water in reference conditions. Water potential of distilled water = 0 (highest) 水潛能(水勢)是指相對於純水而言某種狀態下的單位體積的水的勢能。 蒸餾水的水潛能 = 0 (最高) Experiment 實驗 Cell membrane = dialysis tubing 細胞膜 = 透析管 利用 capillary tube check 有無 water in and out 記錄 change in the liquid level in capillary tube (毛細管中液面位置的改變) 去 check the rate of osmosis (滲透速率) 16 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 Factors affect the rate of osmosis 影響滲透速率的因素 1. temperature 1. 溫度 T increase, K.E. increase, speed increase, less time is required for osmosis 溫度上升、動能上升、速度上升、滲透的所需時間較短 2. difference in water potential 2. 水潛能(水勢)的相差 - difference in water potential increase, the greater the net movement of solvent molecules through a selectively permeable membrane from high water potential to low water potential - 水潛能(水勢)的相差上升，由高水潛能(水勢)到低水潛能(水勢)的溶劑 分子經選擇透性膜的淨移動上升。 3. surface area of selectively permeable membrane 3. 選擇透性膜的表面積 - larger surface area will provide more site to carry out osmosis, the rate of osmosis increase - 較大的表面積會提供更多地方執行滲透，滲透速率上升。 17 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 Plant cells 植物細胞 1. The water potential of cell A is higher than that of surrounding solution Water moved out of the cells, cells became flaccid. 細胞 A 的水潛能(水勢)較週圍溶液的水潛能(水勢)為高， 水從細胞流出，細胞變得軟縮。  plasmolysis 質壁分離 The water potential of the cell sap of the cell is greater than the solution surrounding. Water moves out of the cell by osmosis. The vacuole shrinks in size pulling the cytoplasm & cell membrane away from the cell wall & chloroplasts condense to the centre of the cell 細胞中的細胞液之水潛能(水勢)高於鄰近的溶液。 水因滲透作用離開細胞，液泡縮小， 並將細胞質和細胞膜扯離細胞壁， 及葉綠體聚集在細胞的中央。 2. The water potential of cell A is lower than that of surrounding solution Water moved into the cells, cells became turgid and did not burst because of the presence of the inelastic cell wall. Central vacuole also became turgid. 細胞 A 的水潛能(水勢)較週圍溶液的水潛能(水勢)為低， 水從細胞流入，細胞變得硬脹 及因為無彈性細胞壁的存在，它不會破裂 中央液泡亦會變得硬脹。 18 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 Remarks: 1. Selectively permeable membrane = cell membrane 選擇透性膜 = 細胞膜 2. boiled potato strips will destroy the cell membrane  freely permeable 煮熟的馬鈴薯條會破壞細胞膜  自由進出 3. potato after storing a period of time (insoluble) starch  (soluble) sugar water potential decrease 馬鈴薯經過一段時間的貯存 (不溶於水的) 澱粉  (溶於水的) 糖 4. Skin of fruit acts as a barrier to water 水果的皮會阻隔水份 19 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 Animal cells 動物細胞 1. The water potential of cell A is higher than that of surrounding solution Water moved out of the cells, cells shrank and became wrinkled. (Red blood cells shrank and became crenated) 細胞 A 的水潛能(水勢)較週圍溶液的水勢為高， 水從細胞流出，細胞因萎縮而變得皺褶。 (血紅細胞會收縮及變成圓鋸齒狀) 2. The water potential of cell A is lower than that of surrounding solution Water moved in the cells, cells expanded and burst. 細胞 A 的水潛能(水勢)較週圍溶液的水潛能(水勢)為低， 水向細胞流入，細胞因而膨脹及爆裂。 (if cell A is red blood cell, the above process called Haemolysis of red blood cells: releasing the haemoglobin to the solution and make the solution red) (若細胞 A 是紅血細胞，以上過程名為 溶血作用︰ 釋出其內的血紅蛋白，令溶液變成紅色。) Remarks: Hypotonic solution 低滲溶液 High water potential 高水勢 Isotonic solution 等滲溶液 Same water potential 相同水勢 Hypertonic solution 高滲溶液 Low water potential 低水勢 20 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1diii.movement of substance across the membrane – active transport 物質穿越細胞膜的過程 – 主動轉運 Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration (against the concentration gradient). 1. Active transport requires energy 2. Active transport requires a carrier protein. 3. Active transport can transport substances against a concentration gradient 4. e.g. glucose moves across the epithelium of the ileum 主動轉運是一種由低濃度區域到高濃度區域 (逆濃度梯度) 跨細胞膜的運動。 1. 主動轉運需要能量。 2. 主動轉運需要載體蛋白。 3. 主動轉運能把物質逆濃度梯度移動。 4. 例子︰葡萄糖穿越迴腸上皮 1div. movement of substance across the membrane – phagocytosis 物質穿越細胞膜的過程 – 吞噬 Phagocytosis is the process by which a cell uses its plasma membrane to engulf a large particle, giving rise to an internal compartment called the phagosome. 1. Phagocytosis requires energy 2. For some cell, phagocytosis is a mean to obtain nutrients 3. For immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. 吞噬作用是通過質膜攝取大的粒子，並在其內部形成吞噬體的過程。 1. 吞噬作用需要能量。 2. 對於一些細胞，吞噬作用是為了獲取營養物質。 3. 對於免疫系統，吞噬作用是清理病原體和細胞碎片的主要機制。 21 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1ei. cell cycle & cell division – Definition 細胞週期及細胞分裂 – 定義 DNA controls the formation of proteins such as enzymes which catalyse chemical reactions in the cells so as to control the metabolic activities of the cells. DNA 控制蛋白質的形成，例如催化細胞中化學反應的酶，以致控制細胞的代謝 活動。 Chromosome carries genetic materials of the cell and controls all the activities within the cell. 染色體含有細胞的遺傳物質及控制細胞內所有活動。 22 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1eii. cell cycle & cell division – mitosis 細胞週期及細胞分裂 – 有絲分裂 1. Interphase 間期 (Cell growth 細胞生長) - synthesis of new proteins (n) / synthesis of cell organelles e.g. mitochondrion, endoplasmic reticulum 合成蛋白質/ 合成細胞器 (例︰線粒體、內質膜) (n) (未必做做足兩倍) - genetic materials are dispersed / loosely packed (which indicates that the DNA molecules are ready for transcription 遺傳物質散開/鬆散，顯示 DNA 分子隨時可以進行轉錄 - duplication of DNA (n2n) 複製 DNA (n2n) - chromosome are invisible, DNA is in the format of chromatin 染色體不能觀察，DNA 以染色質的形態存在 2a. Prophase 前期 - nuclear membrane breaks down 核膜消失 - each chromosome shorten and thicken and split into 2 chromatids 每條染色體縮短、變粗，及分為 2 條染色單體 2b. Metaphase 中期 - Chromosomes arrange themselves at the equator of the spindle 染色體排列在紡錘體的赤道上 2c. Anaphase 後期 - The two (sister) chromatids of each chromosome separate and move to opposite poles of the cell 染色體的兩條(姊妹)染色單體分離，並移向細胞的兩極。 2d. Telophase 末期 - 2 diploid nuclei are formed (n) 兩個二倍體細胞核形成 (n) 3. Cytoplasmic division 胞質分裂 - 2 diploid daughter cells are formed 形成 2 個二倍體的子細胞 DNA content DNA 含量 23 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1eiii. cell cycle & cell division – meiosis 細胞週期及細胞分裂 – 減數分裂 1. Interphase 間期 (Cell growth 細胞生長) - synthesis of new proteins (n) / synthesis of cell organelles e.g. mitochondrion, endoplasmic reticulum (未必做做足兩倍) 合成蛋白質/ 合成細胞器 (例︰線粒體、內質膜) (n) - genetic materials are dispersed / loosely packed (which indicates that the DNA molecules are ready for transcription 遺傳物質散開/鬆散，顯示 DNA 分子隨時可以進行轉錄 - duplication of DNA (n2n) 複製 DNA (n2n) - chromosome are invisible, called chromatin 染色體不能觀察，稱染色質 2a. Prophase I 前期 I - nuclear membrane breaks down 核膜消失 - each chromosome shorten and thicken and split into 2 chromatids 每條染色體縮短、變粗，及分為 2 條染色單體 - Homologous chromosomes pair up 同源染色體配對起來 - Crossing over may occurs 可能發生互換 2b. Metaphase I 中期 I - Homologous chromosomes arrange themselves at the equator of the spindle 同源染色體排列在紡錘體的赤道上 2c. Anaphase I 後期 I - The two members of each homologous chromosome pair separate and move to opposite poles of the cell 每對同源染色體的兩個成員各自分離，並移向細胞的兩極。 2d. Telophase I 末期 I - 2 haploid nuclei are formed (n) 兩個單倍體細胞核形成 (n) 24 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 3a. Prophase II 前期 II - Chromosome shorten and thicken 染色體縮短、變粗 3b. Metaphase II 中期 II - Chromosomes arrange themselves at the equator of the spindle 染色體排列在紡錘體的赤道上 3c. Anaphase II 後期 II - The (sister) chromatids of each chromosome separate and move to opposite poles of the cell 染色體的兩條(姊妹)染色單體分離，並移向細胞的兩極。 3d. Telophase II 末期 II - 4 haploid nuclei are formed (n/2) 4 個單倍體細胞核形成 (n/2) 4. Cytoplasmic division 胞質分裂 - 4 haploid daughter cells are formed 形成 4 個單倍體的子細胞 Which structure in which meiosis take place 減數分裂發生在哪個結構? Human : testis, ovary 人類︰睪丸、卵巢 Plant : anther, ovary 植物︰花藥、子房 25 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1eiv. cell cycle & cell division – mitosis vs. meiosis 細胞週期及細胞分裂 – 有絲分裂 vs. 減數分裂 Differences 1. Pairing of homologous chromosomes along the equatorial plane in first division of meiosis but no such process in mitosis. 2. The pairs of homologous chromosomes segregate into the daughter nuclei during the first meiotic cell division Significance - Such that the daughter cells formed contain the whole set of chromosome / one member of each homologous pairs after meiosis - Random segregation of homologous chromosomes results in variations between gametes formed in meiosis - Crossing over may occurs, the exchange of genetic materials between non-sister chromatids gives rise to new genetic combinations 相異之處︰ 1. 在減數分裂的第一分裂時同源染色體在細胞的赤道上配對。 有絲分裂則沒有這一步驟。 2. 在減數分裂時第一分裂時同源染色體分離然後分配到子細胞核內。 意義/重要性︰ - 令減數分裂形成的子細胞均有一套染色體/源染色體的一個成員。 - 同源染色體的隨機分離引致配子之間的變異 - 可換可能進行，染色單體之間的遺傳物質交換導致新的基因組合。 26 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 Differences 3. Mitosis involves one division only but meiosis involves two divisions Significance - The daughter cells resulted from mitosis are genetically identical to the parent cell which is important for growth of the organisms / asexual reproduction - The daughter cells / gametes formed in resulted from meiosis contain half / haploid the genetic content of the parent cell such that the amount of genetic content can be restored after fertilization. 相異之處︰ 3. 有絲分裂只有一次分裂而減數分裂則有兩次分裂 意義/重要性︰ - 由有絲分裂衍生出來的子細胞與親代細胞在基因含量上完全相同，這對生 物的生長具重要性 / 無性生殖 - 由減數分裂衍生出來的子細胞 / 配子只有親代細胞的一半基因含量。 令受精後的合子基因含量回復正常。 Mitosis 有絲分裂 Meiosis 減數分裂 1. separate (sister) chromatids 1. separate homologous chromosomes 分開 (姊妹) 染色單體 分開同源染色體 2. separate (sister) chromatids to form gametes 分開 (姊妹) 染色單體形成配子 27 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fi. metabolism – catabolism & anabolism 代謝作用 – 分解代謝和合成代謝 Metabolism is the inclusive term for all the chemical reactions taking place in living cells. 代謝作用包括所有細胞內進行的化學反應。 2 types of Metabolism (Chemical reaction) : catabolism and anabolism 兩類代謝作用 (化學反應)︰分解代謝 和 合成代謝 Catabolism : breakdown of complex molecules to release energy 分解代謝︰分解複雜分子放出能量 a. digestion of starch by amylase 澱粉酶消化澱粉 b. glycogen  glucose 糖原  葡萄糖 c. glucose (6C)  pyruvate (3C) 葡萄糖 (6C)  丙酮酸鹽 (3C) d. protein  amino acid 蛋白質  氨基酸 e. amino acids  urea 氨基酸  尿素 f. break down of excess amino acids in the liver 在肝臟分解過量的氨基酸 Anabolism : Absorb energy to build up of complex molecules 合成代謝︰吸收能量結合複雜分子 a. production of lipase in the pancreas 在胰臟產生脂肪酶 b. glucose  glycogen 葡萄糖  糖原 Remarks: Physical reaction 物理反應 a. Emulsification of fat 乳化脂肪 28 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 29 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fii. metabolism – Enzymes 代謝作用 – 酶 - biological catalysts - speed up chemical reactions in metabolism - properties : a. lower the activation energy of the chemical reaction (formation of complex lowers the energy barrier of the reaction) b. enzymatic reactions are reversible c. are made up of proteins, so it is denatured at high temperature d. specific enzyme with unique active sites / substrate binding sites that fit with specific substrates for controlling cellular metabolism each enzyme (key) fits only one or a few substrates (lock) (substrate + enzyme = enzyme-substrate complex) e. reusable, so only small amount is sufficient - 生物催化劑 - 加速代謝作用的化學反應 - 特性︰ a. 降低化學反應的活化能 (複合物形成後會降低化學反應的能障) b. 酶催化反應是可逆的 c. 是由蛋白質構成，所以於高溫下會變質 d. 專一性 酶有獨特的活性部位/受質結合部位，與專有的受質結合，以控制不同 的細胞代謝 每種酶 (鑰) 只能適合一或數種 受質 (鎖) (受質 + 酶 = 酶受質複合物) e. 可重複使用，所以少量已足夠 30 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fiii. metabolism – Rate of reaction 代謝作用 – 反應速率 Factors affecting the rate of enzymatic reactions (not the yield) 1. from low temperature to optimum temperature The rate of enzymatic reaction increase, due to the substrate molecules have more kinetic energy (Enzyme collides with substrate more frequently) 2. substrate concentration decrease : reduce the chance of collision between the substrate and enzyme molecules, the rate of enzymatic reaction decrease substrate is used up : reaction stopped 3. low temperature : inactivates the enzyme 4. high temperature : enzymes are denatured (since enzyme are proteins) 5. extreme pH : enzymes are denatured 影響酶反應速率的因素: (不是產量) 1. 由低溫至最適溫度 酶反應速率上升，因為受質分子有較多動能 (酶與受質碰撞更為頻密) 2. 受質濃度下降︰減少受質和酶分子的碰撞機會，酶反應速率下降 受質用完後︰反應停止 3. 低溫︰使酶不活動 4. 高溫︰酶會變性 (因為酶是蛋白質) 5. 極端 pH︰酶會變性 31 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fiv. metabolism – Inhibitor 代謝作用 – 抑制劑 - competitive inhibitor - similar to the substrate molecules - compete with substrates for the active sites on the enzyme molecules - when substrate concentration increase, the rate of enzymatic reaction increase to the level similar to that without adding competitive inhibitor - non-competitive inhibitor - not similar to the substrate molecules - bind with enzyme in such a way that it reduces the catalytic properties of the enzyme - the inhibitory activity cannot be overcome by increasing the substrate concentration - 競爭性抑制劑 - 分子形狀與受質相似 - 跟受質分子競爭的活性位置 - 當提高受質的濃度時，卻可以增加酶反應速率至與沒有加入競爭性抑 制劑的反應速率相若。 - 非競爭性抑制劑 - 分子形狀與受質不相似 - 與酶結合的方法令酶的催化活性降低 - 增加受質的濃度不能克服抑制劑的活動 32 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fv(1). metabolism – 5 Common enzyme experiments 1 : Amylase 代謝作用 – 5 個常見酶實驗 1︰澱粉酶 Amylase : starch  maltose (reducing sugar) 澱粉酶︰澱粉  麥芽糖 (還原糖) - monitor the amylase activity 監察澱粉酶的活動 1. iodine test : add iodine solution Starch present : blue-black colour is observed Starch absent : (light/reddish) brown colour is observed 碘液試驗︰加上碘液 澱粉存在︰觀察到藍黑色 澱粉不存在︰觀察到(淺/紅)棕色 2. benedict test : boil the mixture with excess Benedict’s solution Reducing sugar present : red precipitate is formed 本立德試驗︰將過量本立德溶液加入混合液及加熱 還原糖存在︰會形成紅色沉澱物 - amylase appear in saliva, pancreas, germinating seeds or secreted by bread mould 澱粉酶出現於唾液、胰臟、萌發種子中 或 麵包黴分泌出來 33 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fv(1). metabolism – 5 Common enzyme experiments 1 : Amylase 代謝作用 – 5 個常見酶實驗 1︰澱粉酶 Compare the amylase activities of 2 sources 比較 2 個來源的澱粉酶活性 - Experiment A 實驗 A︰ 1. obtain digestive juice 獲取消化液 2. mix 1 mL of digestive juice with 5 mL of starch solution 用 1 mL 消化液與 5 mL 澱粉溶液混合 3. at regular time intervals, remove a fixed amount of the mixture for iodine test and record the time taken for the tested mixture to stay in brown colour 每隔一段時，抽取定量的混合物以進行碘液試驗，記錄混合物變成褐 色的時間 / 混合物的藍色消失的時間 4. the shorter the time, the faster the digestion of starch, i.e. higher amylase activity 所需的時間愈短，代表澱粉的消化愈快，顯示澱粉酶活性較高 - Experiment B 實驗 B︰ 1. obtain digestive juice 獲取消化液 2. drill two holes on a starch agar plate, add the digestive juices to the holes of starch agar plate respectively 在澱粉瓊脂平板鑽兩小洞，把消化液分別加進小洞內 3. incubate the plate for 30 minutes, add iodine solution to the plate and rinse, compare the brown / clear zones appeared 培養 30 分鐘後，在瓊脂平板加上碘液，然後沖洗， 比較出現的啡色/清澈區域 4. the one with bigger brown / clear zone shows more starch digestion, i.e. higher amylase activity 棕色/清徹區域較大代表較多澱粉消化，顯示澱粉酶活性較高 34 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fv(1). metabolism – 5 Common enzyme experiments 1 : Amylase 代謝作用 – 5 個常見酶實驗 1︰澱粉酶 Compare the amylase activities of 2 sources 比較 2 個來源的澱粉酶活性 - Experiment C 實驗 C︰ 1. obtain digestive juice 獲取消化液 2. mix 1 mL of digestive juice with 5 mL of starch solution 用 1 mL 消化液與 5 mL 澱粉溶液混合 3. After 10 minutes, boil the mixture with excess Benedict’s solution, and record the amount of red precipitate formed 混合十分鐘後，將過量本立德溶液加入混合液中，並進行加熱， 記錄紅色沉澱物生成的數量 4. the one with more red precipitate shows more maltose formation, i.e. a higher amylase activity 較多磚紅色沉澱物生成代表較多麥芽糖生成，顯示澱粉酶活性較高 35 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fv(2). metabolism – 5 Common enzyme experiments 2 : Protease 代謝作用 – 5 個常見酶實驗 2︰蛋白酶 Protease : protein  polypeptide / amino acids 蛋白酶︰蛋白  多肽 / 氨基酸 - monitor the protease activity 監察蛋白酶的活動 1. the reduction in size of protein cubes 蛋白質方塊的體積減少 2. time taken for the disappearance of the egg white cube 蛋白立方塊消失所需時間 3. Biuret test 2 cm3 of (sodium / potassium) hydroxide solution and a few drops of copper sulphate solution are added to the mixture Protein present : violet colour is observed Protein absent : blue colour is observed 雙縮脲法 2 cm3 的氫氧化 (鈉/鉀) 溶液及數滴 硫酸銅溶液 加入溶合物 蛋白質存在︰觀察到紫色 蛋白質不存在︰觀察到藍色 - protease digests the proteins into small molecules (peptides) which can dissolve in water, so it is used as biological washing powder, meat tenderizer 蛋白酶消化蛋白質至細小分子(肽)，使其溶於水 所以用作生物活性洗衣粉及鬆肉粉 - protease appear in stomach, pancreas and small intestine 蛋白酶出現於胃、胰臟及小腸中 - silk and wool also contain protein Jelly contain protein “gelatin” : causes the jelly solution to solidify after cooling 絲和羊毛都包含蛋白質 啫喱包含蛋白質 “白明膠” : 令啫喱溶液冷卻後變成固態 1fv(3). metabolism – 5 Common enzyme experiments 3 : Ginger milk curd 代謝作用 – 5 個常見酶實驗 3︰薑汁撞奶 Enzyme in raw ginger juice : soluble milk protein  insoluble (coagulation) 新鮮薑汁中的酶︰可溶的牛奶蛋白質  不可溶 (凝固) 36 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1fv(4). metabolism – 5 Common enzyme experiments 4 : Lipase 代謝作用 – 5 個常見酶實驗 4︰脂肪酶 Lipase : Triglyceride / fat  glycerol + fatty acid 脂肪酶︰甘油三脂 / 脂肪  甘油 + 脂肪酸 - monitor the lipase activity 監察脂肪酶的活動 1. pH indicator / pH meter pH 指示劑 / pH 計 2. compare the size of stains after washing 比較清洗後污漬的大小 - lipase appear in small intestine 脂肪酶出現於小腸中 - lipase digests the fat stain into fatty acids and glycerol, which both are soluble in water, so it is used as biological washing powder 脂肪酶消化脂肪至溶於水的脂肪酸及甘油， 所以用作生物活性洗衣粉 1fv(5). metabolism – 5 Common enzyme experiments 5 : Catalase 代謝作用 – 5 個常見酶實驗 5︰過氧化氫酶 Catalase : hydrogen peroxide  water + oxygen 過氧化氫酶︰過氧化氫  水 + 氧氣 - monitor the catalase activity 監察過氧化氫酶的活動 1. effervescence 泡騰 2. temperature increase 溫度上升 - one of products : oxygen can relit the glowing splint 其中一個產品︰氧氣可令餘燼的木條重燃 37 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gi. Photosynthesis – experiment tools 光合作用 – 實驗工具 1. Test the presence of carbon dioxide 測試二氧化碳的存在 Carbon dioxide can turn limewater milky 二氧化碳令石灰水變成乳白色 2. Test the concentration of carbon dioxide 測試二氧化碳的濃度 Hydrogencarbonate indicator (bicarbonate indicator) - concentration of carbon dioxide CO2 > normal colour : from red to yellow (more acidic) - concentration of carbon dioxide CO2 < normal colour : from red to purple (less acidic). 碳酸氫鹽指示劑 (重碳酸鹽指示劑) - 二氧化碳濃度 CO2 > 正常︰由紅轉黃 (酸度增加) - 二氧化碳濃度 CO2 < 正常︰由紅轉紫 (酸度減少) (* carbon dioxide is an acidic gas 二氧化碳為酸性氣體) 3. Maintain a constant level of carbon dioxide 將二氧化碳含量保持穩定水平 / Release carbon dioxide / 放出二氧化碳 - Sodium hydrogen carbonate solution - 碳酸氫鈉溶液 4. Absorb carbon dioxide 吸收二氧化碳 - Soda lime 鹼石灰 - concentrated sodium hydroxide 濃氫氧化鈉 - concentrated potassium hydroxide 濃氫氧化鉀 38 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gi. Photosynthesis – experiment tools 光合作用 – 實驗工具 5. Test the presence of starch in the leave 測試葉片中澱粉的存在 a. boil the leaves in water for 2 minutes 置葉於水中煮沸 2 分鐘。 b. immerse the leaves in alcohol heated in a hot water bath (decolourize the leave by dissolving the chlorophyll) 利用熱水浴將酒精加熱，並將葉浸於酒精內。 (溶解葉綠素令葉片褪色) c. soak the leaves in warm water 將葉浸於溫水中。 d. add iodine solution 加入碘液。 [Starch present : blue-black colour is observed Starch absent : (light/reddish) brown colour is observed 澱粉存在︰觀察到藍黑色 澱粉不存在︰觀察到(淺/紅)棕色] 6. Destarch the plant 將植物脫澱粉 Put the plant in darkness for a few days Reason : a. starch in the leaves is converted to sugars which are transported away from the leaves / oxidized in respiration b. to make sure that the starch detected at the end of the experiment was made during the experiment 將植物放在黑暗中數日 a. 葉片內的澱粉轉化糖，並從葉片運走/在呼吸作用時氧化 b. 這可確保在實驗結束時所驗得的澱粉，是在實驗進行期間產生的 7. Independent vs. controlled variable 自變項控制變項 e.g. investigate how different temperature can affect the rate of photosynthesis Independent variable : temperature Controlled variable : CO2 concentration, light intensity, pH value e.g. 研究不同溫度如何影響光合作用的速率 自變項︰溫度 控制變項︰二氧化碳濃度、光度、pH 度 39 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gii. Photosynthesis – basic knowledge 光合作用 – 基本知識 1. water + carbon dioxide + light chlorophyl l carbohydrate + oxygen 水 + 二氧化碳 + 光能 葉綠素  碳水化合物 + 氧氣 2. anabolic process 合成代謝 3. light / solar energy  chemical energy 光 / 太陽能  化學能 4. inorganic substances  organic food 無機物質  有機食物 5. reduce the atmospheric carbon dioxide concentration 減少大氣中的二氧化碳濃度 6. occurs in green plant cells, algae and some bacteria 於綠色植物的細胞、海藻和某些細菌中發生 40 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1giii. Photosynthesis – factors input 光合作用 – 輸入的因素 1. water 水 2. carbon dioxide 二氧化碳 [sodium hydroxide solution = 氫氧化鈉溶液、water = 水、light = 光] 3. light / solar energy 光能 / 太陽能 4. chloroplast / chlorophyll 葉綠體 / 葉綠素 - non-green region of leave cannot carry out photosynthesis. 葉片中非綠色部分不能進行光合作用  Photosynthesis output : starch + iodine : starch present : blue-black starch absent : (light/reddish) brown 光合作用輸出︰澱粉 + 碘液︰澱粉存在︰藍黑色 澱粉不存在︰(淺/紅)棕色 41 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1giv. Photosynthesis – rate 光合作用 – 速率 Factors affecting the rate 影響速率的因素 1. Different colour 不同顏色 [lamp = 燈、colour filter = 顏色濾光片、gas / oxygen = 氣 / 氧、water = 水、 waterweed = 水草] 2. Light intensity 光強度 42 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1giv. Photosynthesis – rate 光合作用 – 速率 3. Concentration of carbon dioxide 二氧化碳濃度 4. Temperature 溫度 Method of measuring the rate 量度速率的方法 1. measure the number of oxygen bubbles released over a period of time. 量度在某段時間內釋出的氧氣泡數目。 2. measure the volume of oxygen gas produced over a period of time. 量度在某段時間內產生的氧氣體積。 3. measure the time for the leaf discs to rise to the surface 量度葉圓片升到表面的時間。 43 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gv. Photosynthesis – photosynthesis rate vs. respiration rate 光合作用 – 光合作用速率 vs. 呼吸作用速率 1. Photosynthesis vs. respiration 光合作用 vs. 呼吸作用 a. Photosynthesis 光合作用 6CO2 + 6H2O + light energy 光能  C6H12O6 + 6O2 b. Respiration 呼吸作用 C6H12O6 + 6O2  6CO2 + 6H2O + energy 能量 2. The rate of respiration of plant is constant throughout the 24-hour period. 在 24 小時整段時間內，植物的呼吸作用速率是恆定的。 3. Under different time 於不同時間 a. In day time 於日間 Photosynthesis rate > Respiration rate Volume of oxygen increase Food production > food consumption Plant can grow and produce fruits 光合作用速率 > 呼吸作用速率 氧氣的體積上升 食物生產 > 食物消耗 植物生長及生產果實 b. In night time 於夜間 Photosynthesis rate < Respiration rate Volume of oxygen decrease 光合作用速率 < 呼吸作用速率 氧氣的體積下降 44 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gvi. Photosynthesis – limiting factors 光合作用 – 限制因素 Light intensity vs. concentration of carbon dioxide vs. temperature 光強度 vs. 二氧化碳濃度 vs. 溫度 Limiting factors 限制因素 = pull the back leg 拖後腳 1gvii. Photosynthesis – light reaction & dark reaction 光合作用 – 光反應、暗反應 Light reaction 光反應 : - 12H2O + light 光  24H + 6O2 Light-independent reaction / Dark reaction 暗反應︰ - 6CO2 + 24H (+ enzyme 酶)  C6H12O6 (simple sugar 單糖) + 6H2O - can also take place under sunlight 陽光下亦可進行 45 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gviii. Photosynthesis – chloroplast 光合作用 – 葉綠體 1. Chloroplast is an organelle, while green pigment molecules inside chloroplast is chlorophyll 葉綠體是細胞器，於葉綠體內的綠色色素分子是葉綠素。 2. 3. Granum / thylakoids a. carry out photochemical reaction Stroma a. carry out Calvin cycle b. storage the product of photosynthesis c. contain enzymes 基粒 / 類囊體 a. 執行光化學反應 基質 a. 執行卡爾文循環 b. 儲藏光合作用產物 c. 含有酶 1gix. Photosynthesis – photochemical reactions & carbon fixation (Calvin cycle) 光合作用 – 光化學反應 與 碳固定 (卡爾文循環) Process of photosynthesis : photochemical reactions + carbon fixation (Calvin cycle) 光合作用的過程︰光化學反應 + 碳固定 (卡爾文循環) 46 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gix. Photosynthesis – photochemical reactions & carbon fixation (Calvin cycle) 光合作用 – 光化學反應 與 碳固定 (卡爾文循環) Photochemical reactions / Light reaction 光化學反應 / 光反應: 1. Light : electron in chlorophyll become excited 光︰葉綠素中的電子被激發 Chlorophyll  Chlorophyll+ + e– 葉綠素  葉綠素+ + e– 2. Electrons flow to thylakoid membrane, so that thylakoid membrane become negatively charged 電子流到類囊體膜，令類囊體膜變成負極 3. Hydrogen ions pulled into thylakoid 氫離子拉入類囊體 4. Water molecules are broken in thylakoid membrane The H+ is obtained from photolysis of water under light: 於類囊體膜中，水分子被拆開 於光照射下，H+ 來自水的光解︰ 1 H2O  2H+ + O2 + 2e– 2 5. electrons from water replenish the chlorophyll ion in step 1 來自水的電子補充給第 1 步的葉綠素離子 Chlorophyll+ + e– (come from photolysis of water)  Chlorophyll 葉綠素+ + e– (來自水的光解)  葉綠素 6. oxygen gas waste released 釋出氧氣廢料 7. Light : electron in chlorophyll become excited 光︰葉綠素中的電子被激發 Chlorophyll  Chlorophyll+ + e– 葉綠素  葉綠素+ + e– 8. In stroma, electrons help bond NADPH from NADP+ and hydrogen ions 於基質，電子幫助將 NADP+ 及氫離子 鍵合 NADPH NADP+ + H+ + 2e–  NADPH 9. Hydrogen ions in step 3 diffuses from thylakoid into stroma 第 3 步的氫離子由類囊體向基質擴散 10. Photophosphorylation 光磷酸化作用 Hydrogen ions helps bond ATP from ADP and inorganic phosphate (Pi) 氫離子幫助由 ADP 及磷酸鹽 (Pi) 鍵合 ATP ADP + Pi  ATP Product 產物 : O2 + NADPH + ATP 47 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gix. Photosynthesis – photochemical reactions & carbon fixation (Calvin cycle) 光合作用 – 光化學反應 與 碳固定 (卡爾文循環) Carbon fixation (Calvin cycle / light independent reaction / dark reaction) 碳固定 (卡爾文循環 / 暗反應) 1-C : carbon dioxide 二氧化碳 5-C : carbon dioxide acceptor 二氧化碳受體 3-C : 3-C compound 三碳化合物 6-C : glucose (C6H12O6) 葡萄糖 (C6H12O6) 1. 6(1-C:Carbon dioxide) + 6(5-C:carbon dioxide acceptor)  12 (3-C) 6(1-C:二氧化碳) + 6(5-C:二氧化碳受體)  12 (3-C) 2. Reduction of 3-C compound leading to the formation of glucose ATP provides energy to drive the light-independent reaction / for the regeneration of CO2 acceptor (5-C) NADPH provides reducing power for the reduction of 3-C compound to form glucose 三碳化合物的還原，以生成葡萄糖 ATP 提供能量，推動暗反應 / 供再生二氧化碳受體之用 NADPH 提供還原力，將三碳化合物還原，產生葡萄糖 2a. 12(3-C) + 12ATP + 12NADPH  12(3-C sugar : triose phosphate) + 12ADP + 12NADP 12(3-C) + 12ATP + 12NADPH  12(3-C 糖︰丙酮磷酸) + 12ADP + 12NADP 2b. 2 (3-C sugar : triose phosphate)  1 (6-C) 2 (3-C 糖︰丙酮磷酸)  1 (6-C) 3. Regeneration of carbon dioxide acceptor 二氧化碳受體的再生 10 (3-C sugar : triose phosphate) + 6ATP  6 (5-C:carbon dioxide acceptor) + 6ADP 10 (3-C 糖︰丙酮磷酸) + 6ATP  6 (5-C:二氧化碳受體) + 6ADP Overall : 6H2O + 6CO2 + light 光  C6H12O6 + 6O2 48 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1gx. Photosynthesis – photosynthetic products 光合作用 – 光合作用產物 Photosynthetic products - Triose phosphate : (1) Glucose (2) Glycerol - 3-C Compound  Pyruvate : (3) Fatty acids (4) Amino acids (1) Glucose - used in respiration -  starch : for storage -  cellulose : component of cell wall (2) Glycerol + (3) Fatty acids -  Lipids : component of cell membrane (4) Amino acids -  Protein 光合作用產物 - 丙糖磷酸︰ (1) 葡萄糖 (2) 甘油 - 三碳化合物  丙酮酸鹽︰(3) 脂肪酸 (4) 氨基酸 (1) 葡萄糖 - 於呼吸作用中使用 -  澱粉︰貯藏 -  纖維素︰細胞壁的成份 (2) 甘油 + (3) 脂肪酸 -  脂質︰細胞膜的成分 (4) 氨基酸 -  蛋白質 49 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hi. Respiration – experiment tools 呼吸作用 – 實驗工具 1. Test the presence of carbon dioxide 測試二氧化碳的存在 Carbon dioxide can turn limewater milky 二氧化碳令石灰水變成乳白色 2. Test the concentration of carbon dioxide 測試二氧化碳的濃度 Hydrogencarbonate indicator (bicarbonate indicator) - concentration of carbon dioxide CO2 > normal colour : from red to yellow (more acidic) - concentration of carbon dioxide CO2 < normal colour : from red to purple (less acidic). 碳酸氫鹽指示劑 (重碳酸鹽指示劑) - 二氧化碳濃度 CO2 > 正常︰由紅轉黃 (酸度增加) - 二氧化碳濃度 CO2 < 正常︰由紅轉紫 (酸度減少) (* carbon dioxide is an acidic gas 二氧化碳為酸性氣體) 3. Maintain a constant level of carbon dioxide 將二氧化碳含量保持穩定水平 / Release carbon dioxide / 放出二氧化碳 - Sodium hydrogen carbonate solution - 碳酸氫鈉溶液 4. Absorb carbon dioxide 吸收二氧化碳 - Soda lime 鹼石灰 - concentrated sodium hydroxide 濃氫氧化鈉 - concentrated potassium hydroxide 濃氫氧化鉀 50 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hii. Respiration – aerobic respiration 呼吸作用 – 需氧呼吸 1. Chemical equation 化學方程式 C6H12O6 + 6O2 mitochondr  ia 6CO2 + 6H2O + chemical energy in ATP + heat energy 線粒體 C6H12O6 + 6O2  6CO2 + 6H2O + ATP 中的化學能 + 熱能 2. Word equation 文字方程式︰ Food/glucose + oxygen  carbon dioxide + water + chemical energy in ATP + heat energy 食物/葡萄糖 + 氧  二氧化碳 + 水 + ATP 中的化學能 + 熱能 3. heat energy release  pressure increase 釋出熱能  氣壓上升 4. Respiration involves enzyme 呼吸作用需要酶 5. external temperature rise from 10 C to 60 C  body temperature of animals rises  the enzymatic activity of the animals increases  metabolic rate increase  respiration rate increase 外界溫度由 10 C 升到 60 C  動物的體溫上升  動物的酶活性上升  代謝率上升  呼吸速率上升 6. Sugar / glucose vs. glycogen vs. fats vs. Starch 糖 / 葡萄糖 vs. 糖源 vs. 脂肪 vs. 澱粉 Sugar / glucose : for using in animals 糖/葡萄糖︰動物使用 Glycogen / Fats : for storage in animals 糖源/脂肪︰動物儲藏 Starch : for storage in plants 澱粉︰植物儲藏 7. catabolism 分解代謝 8. animals 動物 / germinating seed 萌芽中的種子 51 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hiii.Respiration – anaerobic respiration 呼吸作用 – 缺氧呼吸 1. Compare with aerobic respiration 與需氧呼吸比較 a. release less energy 釋出較少能量 b. oxidizes food incompletely 對食物的氧化不完全 2. Alcoholic fermentation 酒精發酵︰ a. Glucose  Ethanol + Carbon dioxide + energy yeast 葡萄糖 酵母菌  乙醇 + 二氧化碳 + 能量 b. Yeast can undergo aerobic and anaerobic respiration 酵母菌可以進行需氧呼吸和缺氧呼吸 c. When the concentration of product (ethanol) reach a high level, yeast will be killed. 當產物 (乙醇) 濃度到達某一水平，酵母菌會被殺死。 d. When the concentration of glucose is too high, yeast is also killed by osmosis. 當葡萄糖的濃度過高，酵母菌會因滲透而被殺死。 e. Yeast, is an enzyme, will be denatured at high temperature 酵母菌作為酶，會於高溫下變性。 52 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hiii.Respiration – anaerobic respiration 呼吸作用 – 缺氧呼吸 3. Muscles 肌肉︰ a. Glucose  Lactic acid + energy 葡萄糖  乳酸 + 能量 i. Provide additional energy for the skeletal muscle cells, so that the skeletal muscle can contract more strongly 為了供應額外的能量予骨骼肌細胞使骨骼肌能更劇烈地收縮 ii. lactic acid causes muscle fatigue 乳酸引致肌肉疲勞 b. High level of lactic acid  pH of blood and tissue fluid decrease  adversely affects cellular activities / inactivates enzymes 有大量乳酸  血液和組織液的 pH 下降  對細胞活動有不良影響 / 令酶不活躍 c. During exercise, the speed of blood flow increases i. carry more heat away from muscle ii. increase the oxygen supply to the muscle carry out aerobic respiration 當運動時，血流量會上升 i. 從肌肉帶走更多的熱能 ii. 供應更多氧予肌肉進行需氧呼吸 d. aerobic respiration at the same time 同一時間需氧呼吸 e. After lactic acid is formed, i. breathe quickly, the extra oxygen you breathe in reacts with the lactic acid in your muscles, breaking it down to make carbon dioxide and water. ii. apply some ointment which enhances blood circulation helps to transport lactic acid away from muscle cells more quickly. 當乳酸形成後 i. 快速呼吸，你吸入的額外氧氣會與你肌肉中的乳酸反應， 將其分拆為二氧化碳及水。 ii. 塗上軟膏加速血液循環，幫助從肌肉細胞中快速帶走乳酸。 f. Application of lactic acid fermentation 乳酸發酵的應用 - flavor or preserve diary products and vegetables, e.g. Yakult, yogurt, pickles and kimchi. 為乳製品和蔬菜增味和保存 e.g. 益力多、酸奶、泡菜(黃瓜) 和 泡菜(大白菜) 53 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hiii.Respiration – anaerobic respiration 呼吸作用 – 缺氧呼吸 4. Industrial application of anaerobic respiration 缺氧呼吸的工業應用 a. generate ethanol for the production of biofuel (Yeast) 產出乙醇從而生產生物燃料 (酵母菌) b. sewage treatment (Anaerobic bacteria) break down larger organic matters into inorganic matter (fuels / fertilizers) in sewage 污水處理 (厭氧細菌) 將污水中的大型有機物質分解為無機物質 (燃料/肥料) c. brewing of beer / wine (Yeast) 釀製啤酒 / 酒 (酵母菌) d. bread-making (Yeast) raise the dough  cake / bread become more spongy 製作麵包 (酵母菌) 將麵糰升起  蛋糕 / 麵包變得更鬆軟 54 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hiv. Respiration – glycolysis, Krebs cycle & oxidative phosphorylation 呼吸作用 – 糖酵解、克雷伯氏循環 及 氧化磷酸化 Cytoplasm 細胞質 1. site of Glycolysis 1. 進行糖酵解的位置 2. place to store glycogen 2. 儲藏糖原的地方 Mitochondrion 線粒體 1. site of Kreb cycle (matrix) 1. 進行克雷伯氏循環的位置(基質) 2. site of Oxidative phosphorylation (inner membrane / cristae) 2. 進行氧化磷酸化的位置(內膜/脊) 55 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hiv. Respiration – glycolysis, Krebs cycle & oxidative phosphorylation 呼吸作用 – 糖酵解、克雷伯氏循環 及 氧化磷酸化 Aerobic respiration 需氧呼吸 (1 Glucose 葡萄糖  38 ATP) 1. Glycolysis (Cytoplasm) a. Phosphorylation : Glucose + 2ATP  2 “3-C Compound” (triose phosphate) b. 2 “3-C Compound” (triose phosphate) + 4ADP + NAD  Pyruvate + 4ATP + NADH 糖酵解 (細胞質) a. 磷酸化︰葡萄糖 + 2ATP  2 三碳化合物 (丙糖磷酸) b. 2 三碳化合物 (丙糖磷酸) + 4ADP + NAD  丙酮酸鹽 + 4ATP + NADH 2. Kreb cycle (Matrix of mitochondrion) a. Pyruvate transport to matrix of mitochondrion b. Pyruvate  “2-C compound” (acetyl CoA) + NADH + CO2 c. acetyl CoA + “4-C compound”  “6-C compound” d. “6-C compound” + NAD + FAD + ADP  “4-C compound” + CO2 + NADH + FADH + ATP 克雷伯氏循環 (線粒體的基質) a. 丙酮酸鹽 運送到 線粒體的基質 中 b. 丙酮酸鹽  兩碳化合物 (乙酰輔酶 A) + NADH + CO2 c. 乙酰輔酶 A + 四碳化合物  六碳化合物 d. 六碳化合物 + NAD + FAD + ADP  四碳化合物 + CO2 + NADH + FADH+ ATP 3. Oxidative phosphorylation (inner membrane / cristae of mitochondrion) a. NADH  NAD + H + e– FADH  FAD + H + e– b. H & e– pass through a series of electron carriers H + e– + O2 + ADP  H2O + ATP 氧化磷酸化作用 (線粒體的內膜/脊) a. NADH  NAD + H + e– FADH  FAD + H + e– b. H 及 e– 通過一系列的電子載體 H + e– + O2 + ADP  H2O + ATP 56 © by Herman Yeung www.youtube.com/HermanYeung DSE Biology Chapter 1 - Cells and Molecules of Life 細胞與生命分子 1hiv. Respiration – glycolysis, Krebs cycle & oxidative phosphorylation 呼吸作用 – 糖酵解、克雷伯氏循環 及 氧化磷酸化 Anaerobic respiration 缺氧呼吸 (Cytoplasm 細胞質) (1 Glucose 葡萄糖  2 ATP) 1. Glycolysis a. Phosphorylation : Glucose + 2ATP  2 “3-C Compound” (triose phosphate) b. 2 “3-C Compound” (triose phosphate) + 4ADP + NAD  Pyruvate + 4ATP + NADH 糖酵解 a. 磷酸化︰葡萄糖 + 2ATP  2 三碳化合物 (丙糖磷酸) b. 2 三碳化合物 (丙糖磷酸) + 4ADP + NAD  丙酮酸鹽 + 4ATP + NADH Lactic acid fermentation 乳酸發酵 2. Pyruvate + NADH  lactic acid + NAD 丙酮酸鹽 + NADH  乳酸 + NAD Alcoholic fermentation 酒精發酵 2a. Pyruvate  CO2 + 2-C compound 丙酮酸鹽  CO2 + 兩碳化合物 2b. NADH + 2-C compound  NAD + ethanol NADH +兩碳化合物  NAD + 乙醇 57 © by Herman Yeung www.youtube.com/HermanYeung