SPM Biology Form 4 Notes Terminology and Concepts:

Cell Structure and Cell Organisation

by: AeinnaMusa

by: AeinnaMusa

Cell Structure and Function

Comparison between Animal Cell (AC) and Plant Cell (PC)

1. Mitochondrion (pl: Mitochondria): AC and PC

spherical  / rod-shaped organelles

two membranes : Inner membrane – form cristae & Outer membrane – regular and smooth

an energy source

site of cellular aerobic respiration

produces ATP (adenosine triphosphate)

2. Nucleus (pl: Nuclei): AC and PC

contains the genetic material

regulates  and controls the activities of the cell

an organelle bounded by double (2) layers of nuclear membrane with pores

and selectivelypermeable

responsible for all cellular structure, chemical functions, growth and reproduction

separates  the genetic materials (chromatin) from cytoplasm

3. Nucleolus: AC and PC

spherical  structure within the nucleus

consists of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) and proteins

visible  when the cell is not dividing

synthesis RNA which is needed to make ribosomes

by: AeinnaMusa

4. Nucleoplasm: AC and PC

fluid contained within the nucleus

highly viscous solid

made up of the chromatin and the nucleolus

5. Chromosomes

thread-like structures (consists of genetic material)

appears as chromatin spread throughout the nucleus in the form of tiny granules

chromatin condenses into chromosomes (during cell division)

carry genetic information in its DNA

6. Ribosomes: Ac and PC

small dot-like organelles

protein  synthesis

consist of RNA (ribonucleic acids)

smallest cellular organelles

attached  on the surface of ER and occur freely in cytoplasm

7. Endoplasmic reticulum (ER): AC and PC

connected  to the nuclear membrane

synthesises  proteins, steroids and lipids

collects , stores and distributes protein, steroids and lipids

exists as rough ER and smooth ER

Rough  ER: covered with ribosomes, flat sealed sac which continued from the nuclear

membrane, transports protein, and have a large surface area for chemical reactions.

Smooth  ER: does not have ribosomes, transports lipids and presents in large amounts of

cells.

8. Plasma membrane: AC and PC

cell membrane

thin   membrane surround the cytoplasm of a cell

selectively permeable   / semi permeable

a protective   and selective   outer barrier

consists of phospholipids   and protein   molecules

by: AeinnaMusa

9. Golgi apparatus / Golgi body: AC and PC bound sacs processes , packages   and transport   molecules synthesised in the cell forms lysosomes transports and stores lipids synthesis of carbohydrate   from hormone changes protein into glycoprotein excretes waste   products out of the cell

10. Cytoplasm: AC and PC

aqueous   solution (except nucleus) stores water, enzymes, nutrient, salts   and dissolved gases provided support, shape   and protects   the cell organelles medium   for metabolic reactions provides substances

11. Lysosome: AC sac-like   organelle with one   membrane digest proteins, lipids   and carbohydrates removes   undigested materials releases enzymes   to digest external materials

12.  Centriole: AC

are paired cylindrical   organelles nine tubes   with three tubules   each produces spindle   during cell division (mitosis and meiosis) migrate to the opposite poles   of the cell (during cell division – will be discussed in

Chapter 5 Cell Division)

13. Vacuole: AC (temporary / lower class species) and PC small   cavity in the cytoplasm bound by a single   membrane filled with cell sap storage of food   (protein, oil and water) some vacuoles  remove metabolic waste functions as cell expansion Amoeba: food vacuoles (phagocytosis) Paramecium: contractile vacuoles (expel water)

by: AeinnaMusa

14. Cell Wall: PC rigid and tough cellulose   layer surrounding the plasma membrane (cell membrane) protects   and supports the cell maintains the shape prevents the cell from busting   (excessive intake of water) allows substances to move freely   through the cell wall

15. Chloroplast: PC disc / lens-shaped organelle have two   membranes: inner and outer membrane contains chlorophyll   in the grana to trap sunlight energy carry out photosynthesis   in the chlorophyll storage of food   and pigments

16. Organelles – (little organ) tiny structures inside a cell that perform specific functions for a cell. Example: mitochondria, lysosome and chloroplast.

17. Mitochondria Animal: High density at sperm cells (at middle piece to provide sufficient energy for

motive power), flight muscle cells (bird / avian), liver cells, meristematic / meristemic cells (involve with cell division), kidney cells, heart   muscle cells, brain   cells.

18. Chloroplasts Plant: High density at palisade mesophyll (leaf: below upper epidermis). It functions to

trap sunlight to synthesise sugar during photosynthesis.

The Uniqueness of The CellA cell is unique:

1. Specialisation 2. Division   of labour3. Coordination   and integrationExample of specialisation of cells :

Animal  – smooth muscle cell, neuron (nerve cell), white blood cell, red blood cell (erythrocyte), cheek cell (lining epithelial cell), sperm, ovum cell (the biggest cell in human)

Plant  – palisade mesophyll cell, xylem, phloem, guard cell.

by: AeinnaMusa

Cell OrganisationUnicellular – A single cell performs all the basic life process. Example: Amoeba sp.,Paramecium sp., Chlamydomonas, Bacteria and Euglena.Multicellular – An organism consists of more than one cell. Each group of cell specialized to carry our life processes. Example: Homo sapien (human), animals and plants. It has five levels of organisation1. Cells: basic units of structure and function.

Example: Red blood cells and xylem vessel cells.2. Tissues: made up of cells with similar in structure and function.

Example: Epithelial tissues and vascular tissues.3. Organs: made up of tissues that perform a specific function.

Example: Heart and flower.4. System: two of more organs that perform a specific function.

Example: Digestive system and root system.5. Organisms: whole living thing that carry out all the basic life processes.

Example: Human and durian tree.

Cell Organisation (Unicellular) in Amoeba sp. (lives in freshwater ponds) andParamecium sp. (lives in soil and moist area)1. Cell structure Amoeba sp.: plasma membrane, food vacuole, contractile vacuole, pseudopodium,

nucleus, ectoplasma, endoplasm. Paramecium sp.: food vacuole, posterior contractile vacuole, cytostome, gullet, oral

groove, cilia, macronucleus, micronucleus, anterior contractile vacuole.2. Locomotion Amoeba sp.: Pseudopodium (false foot) helps it to move forward slowly and it is known

asamoeboid movement. Paramecium sp.: Hair-like cilia   to beat against water. It beats its cilia backwards

diagonally (swim forward) and it rotates on its axis. It beats its cilia forward (swim backwards).

3. Feeding Amoeba sp.: Omnivore. Eat bacteria, plant cells, algae and other microscopic organisms.

Entrapment – extend pseudopodium.Engulfment   – engulf tiny food (phagocytosis) with its pseudopodia.Digestion – food enclosed in food vacuoleAbsorption – enzyme digests the bacteriaEgesting – expel indigestible material.

Paramecium sp.: Eat bacteria, organic material and other microscopic organisms.Sweeping – movement of cilia. Food moves along the oral groove into the gullet and cytostome.

by: AeinnaMusa

Digestion – food vacuole circulates round the cell.Elimination – undigested food is eliminated at the anal pore.

4. Reproduction Amoeba sp.: two types of reproduction.

Binary Fission – nucleus divides (favourable condition) and then follows by division of cytoplasm. Two   daughter cells are formed (mitotic division).Spore Formation – spores form (bad condition) and germinate into new amoeba under favourable condition.

Paramecium sp.: two types of reproduction.Binary Fission – micronucleus undergoes mitosis (favourable condition). Macronucleus begins to elongation and form two. Cell content divide and two daughter cells are formed.Conjugation (Sexual reproduction) – two same species parent paramecia exchange genetic material of their micronuclei. Each parent divides and forms four   daughter cells.

5. Osmoregulation Amoeba sp.: water moves into the cell by osmosis and prevention of bursting, it has a

contractile vacuole. Paramecium sp.: water moves into the cell by osmosis and prevention of bursting, it

has two contractile vacuoles.6. Respiration Amoeba sp. and Paramecium sp. (both): exchange gases throughout the whole   cell

membrane7. Excretion Amoeba sp. and Paramecium sp. (both): waste products are ammonia and carbon

dioxide by diffusion. Solid waste in paramecium is expelled through its anal pore.

by: AeinnaMusa

Cell Organisation (Multicellular) in Human

Cells: Epithelial cells, muscle cells, white blood cells, red blood cells, sperm, nerve cells.Tissues: Epithelial tissue, smooth muscle tissue, connective tissue, skeletal tissue, nerve tissue.Organs: Stomach, heart, kidney, lung, liver.Systems: Circulatory system, respiratory system, digestive system, excretory system, muscular system, lymphatic system, integumentary system, skeletal system, nervous system, endocrine system, reproductive system.Organisms: Human.

by: AeinnaMusa

Cell Organisation in Plant

Cells: Parenchyma cells, collenchyma cells, sclerenchyma cells, epidermal cells.Tissues: Epidermal tissue, meristem tissue, vascular tissue.Organs: Leaf organ, flower organ, stem organ, root organ.Systems: Shoot system, root system.Organisms: Plant.

by: AeinnaMusa