Armaans Science Test On Cells

This is a flashcard set for science about cells

Cell Theory

All living things are made up of one or more cells, All cells come from pre-existing cells through cell division, Cells are the basic unit of structure and function in living things.

Nucleus

"Headquarters" of the cell; contains DNA and controls cell activities.

Ribosomes

Make proteins in the ER

Endoplasmic Reticulum

Has ribosomes, makes proteins, and transports proteins

Golgi Bodies (Golgi Apparatus)

Modify, sort, and package proteins and lipids for transport inside or outside the cell.

Cell Wall

Rigid outer layer found in plant cells (and some bacteria); provides support, shape, and protection.

Chloroplast

Site of photosynthesis; contains chlorophyll to capture sunlight energy and turn it into glucose.

Cell Membrane

Protective barrier that controls what enters and leaves the cell; helps with communication between cells.

Cytoplasm

Jellylike substance that fills the cell and holds organelles in place; site of many chemical reactions.

Lysosomes

Break down waste, old cell parts, and invading bacteria; help protect the cell.

Vacuoles

Storage centers for water, nutrients, or waste. Large central vacuole in plant cells maintains structure.

Mitochondria

"Powerhouse" of the cell; makes ATP (energy) through cellular respiration.

Prokaryotic Cells

Simple cells without a nucleus; DNA floats in cytoplasm (e.g., bacteria). Usually unicellular.

Eukaryotic Cells

More complex cells with a nucleus and organelles; found in plants, animals, fungi, and protists.

Diffusion

Movement of molecules from high concentration to low concentration until equilibrium is reached.

Osmosis

Diffusion of water across a selectively permeable membrane; moves from high water concentration to low water concentration.

Cellular Respiration

Oxygen + Glucose → Carbon Dioxide + Water + ATP (energy). Happens in mitochondria.

Photosynthesis

Carbon Dioxide + Water + Sunlight → Glucose + Oxygen. Happens in chloroplasts of plant cells.

Autotrophs

Organisms that make their own food (producers, like plants and algae).

Heterotrophs

Organisms that cannot make their own food; must eat other organisms (consumers).

Stages of Mitosis

Interphase - cell grows, copies DNA, prepares to divide. Prophase - chromosomes condense, nuclear membrane breaks down. Metaphase - chromosomes line up in the middle of the cell. Anaphase - sister chromatids are pulled apart. Telophase - new nuclei form. Cytokinesis - cytoplasm splits, creating two identical cells.

Reasons for Cell Division

Growth, repair of damaged tissue, reproduction, and to prevent cells from becoming too large.