2e - Plant Nutrition

Carbon dioxide concentration

二氧化碳浓度 (èryǎnghuàtàn nóngdù) The amount of carbon dioxide present in the air; a key factor affecting the rate of photosynthesis.

Cellulose

纤维素 (xiānwéisù) A polysaccharide that forms the strong structural component of plant cell walls.

Chlorophyll

叶绿素 (yèlǜsù) Green pigment in chloroplasts that absorbs light energy for photosynthesis.

Chloroplast

叶绿体 (yèlǜtǐ) Organelle within plant cells (especially palisade and spongy mesophyll) where photosynthesis takes place; contains chlorophyll.

Cuticle

角质层 (jiǎozhìcéng) Waxy, waterproof layer covering the leaf epidermis; reduces water loss.

Elodea

伊乐藻 (yīlèzǎo) / 水蕴草 (shuǐyùncǎo) An aquatic plant commonly used in experiments to investigate the rate of photosynthesis by measuring oxygen production.

Guard cells

保卫细胞 (bǎowèi xìbāo) Pairs of specialized cells surrounding a stoma; they control the opening and closing of the pore by changing shape.

Hydrogencarbonate Indicator Solution

碳酸氢盐指示剂 (tànsuānqīngyán zhǐshìjì) A solution that changes color depending on the concentration of CO₂: yellow (high CO₂), orange (normal air), purple (low CO₂). Used to monitor CO₂ levels in experiments.

Iodine solution

碘液 (diǎnyè) Chemical solution used to test for the presence of starch; turns from yellow-brown to blue-black if starch is present.

Leaf epidermis

叶表皮 (yè biǎopí) The protective outer layer of cells on the upper and lower surfaces of a leaf.

Light intensity

光照强度 (guāngzhào qiángdù) The strength or brightness of light; a key factor affecting the rate of photosynthesis.

Limiting factor

限制因素 (xiànzhì yīnsù) A factor (e.g., light intensity, CO₂ concentration, temperature) that, if in short supply, restricts the rate of a process like photosynthesis.

Magnesium deficiency

缺镁 (quē měi) Condition in plants caused by a lack of magnesium ions; leads to yellowing leaves (chlorosis), as magnesium is a component of chlorophyll.

Nitrate deficiency

缺硝酸盐 (quē xiāosuānyán) / 缺氮 (quē dàn) Condition in plants caused by a lack of nitrate ions; leads to stunted growth and yellowing older leaves, as nitrates are needed for proteins and chlorophyll.

Palisade mesophyll cells

栅栏状叶肉细胞 (zhàlánzhuàng yèròu xìbāo) Tightly packed, column-shaped cells in the upper part of the leaf's middle layer (mesophyll); main site of photosynthesis due to many chloroplasts.

Phloem

韧皮部 (rènpíbù) Plant transport tissue that carries sugars (mainly sucrose) made during photosynthesis from the leaves to other parts of the plant (translocation).

Photosynthesis

光合作用 (guānghé zuòyòng) Process in plants using light energy, water, and carbon dioxide to make glucose (food) and oxygen; requires chlorophyll.

Soda lime

碱石灰 (jiǎnshíhuī) A chemical substance that absorbs carbon dioxide; used in experiments to remove CO₂ from the air.

Spongy mesophyll cells

海绵状叶肉细胞 (hǎimiánzhuàng yèròu xìbāo) Loosely arranged cells in the lower part of the leaf's middle layer (mesophyll) with large air spaces between them to allow for gas diffusion.

Starch

淀粉 (植物中) (diànfěn (zhíwù zhōng)) A polysaccharide (carbohydrate) used as an energy store in plants; made from glucose produced during photosynthesis.

Stomata (singular: Stoma)

气孔 (qìkǒng) Small pores, usually on the lower leaf surface, that open and close to allow gas exchange (CO₂ in, O₂ and water vapour out).

Sucrose

蔗糖 (zhètáng) A disaccharide sugar; the main form in which carbohydrates are transported in the phloem of plants.

Temperature

温度 (wēndù) The degree of hotness or coldness; affects the rate of enzyme-controlled reactions in photosynthesis.

Vascular bundle

维管束 (wéiguǎn shù) A strand of conducting vessels (xylem and phloem) in the stem, leaf, or root of a plant, along with associated supporting tissues. Also known as a vein in leaves.

Xylem

木质部 (mùzhìbù) Plant transport tissue that carries water and dissolved mineral ions from the roots to the rest of the plant.