1-2 Notes – The Cell (Part 1) Chapter 1, Lesson 2

Cell Shape and Movement Cell shape and size is related to function

Cell Membrane Found in all cells Protective outer covering Selectively permeable – some things cannot enter a cell, and others cannot leave Flexible layer of phospholipids

Cell Membrane

Cell Membrane

Cell Wall Found in plants, fungi, some bacteria Outside the cell membrane Supports and protects the cell Very rigid Plant cell walls made mostly of cellulose, a carbohydrate

Cell Wall

Cell Appendages An appendage is something that helps you move (arm, leg, wing, flipper) Two kinds: flagella and cilia A flagellum (singular) is a tail-like appendage (can have one or more) Cilia are short, hairlike appendages, and occur in large numbers

Cell Appendages

Cytoplasm A thick fluid made of mostly water Structures and substances in cell are suspended in the cytoplasm

Cytoskeleton Network of fibers responsible for: Muscle contraction Cell division Cell movement Maintenance of cell shape

Cytoskeleton

Cell Organelles Structures suspended in the cytoplasm Have specific functions Not found in single-celled organisms

Nucleus Often called the control center of the cell Surrounded by a membrane Inside is the nucleolus, which helps make proteins

Nucleus Contains genetic material (nucleic acids) for making all the molecules of a cell Long chains of DNA are coiled into structures called chromosomes The same kind of organisms have the same number of chromosomes in each cell (humans have 46, cats have 38, dogs have 78, beans have 22, mosquitoes have 6)

Nucleus

Nucleus

Ribosomes Manufacture proteins Not membrane-bound Found in all cells Made in nucleolus and move into cytoplasm May be attached to the endoplasmic reticulum

Endoplasmic Reticulum (ER) Highly-folded membrane connected to the nucleus’ membrane 2 kinds: rough ER, smooth ER

Endoplasmic Reticulum (ER) Rough ER has ribosomes on its surface, and makes proteins Smooth ER does not have ribosomes, and makes lipids

Mitochondrion (Plural = mitochondria) Food energy is transformed into usable energy here (needed by all living things) Sometimes called the “power house” of a cell Cells that require more energy (muscles) have more mitochondria

Chloroplasts Plants can make their own food in this organelle Use light energy to make food (sugar) Found in nearly all plants and some single-celled organisms Not found in animal cells

What is the function of a flagellum? A transport nutrients 1.2 The Cell What is the function of a flagellum? A transport nutrients B maintain cell shape C store molecules D cell movement

What do mitochondria use to make energy? A food molecules 1.2 The Cell What do mitochondria use to make energy? A food molecules B light energy C water D air

Where is genetic information stored in plant and animal cells? SCI 1.c Where is genetic information stored in plant and animal cells? A nucleus B cell membrane C ribosomes D chloroplasts

Which organelle releases energy for cell functions? A nucleus SCI 1.d Which organelle releases energy for cell functions? A nucleus B chloroplasts C ribosomes D mitochondria

What organelle uses sunlight energy to make food? A cell wall SCI 1.d What organelle uses sunlight energy to make food? A cell wall B chloroplasts C mitochondria D central vacuole